i prefer black, what should i do as white?

Play 1. c3 and pretend that you are Black and your opponent has lost a move.

You might try the suggestions in My First Chess Opening Repertoire for White.
https://www.newinchess.com/media/wysiwyg/product_pdf/9033.pdf
https://chessbookreviews.wordpress.com/tag/vincent-moret/

Some other possibilities are described in Opening Repertoire 1 e4
https://www.newinchess.com/media/wysiwyg/product_pdf/7819.pdf

and A Simple Chess Opening Repertoire for White.

http://www.jeremysilman.com/shop/pc/A-Simple-Chess-Opening-Repertoire-for-White-76p3916.htm

http://www.gambitbooks.com/pdfs/A_Simple_Chess_Opening_Repertoire_for_White.pdf

Since you don't seem to care for your opponent's responses to 1.e4, or many other mainstream openings, you might check out the King's Indian Attack (KIA).  This is a flexible opening system for White which can be played against almost any response by Black...

https://en.wikipedia.org/wiki/King%27s_Indian_Attack

https://www.youtube.com/watch?v=ckAEiBfcRB4

https://www.youtube.com/watch?v=JkuVZZw1vPM

https://www.youtube.com/watch?v=j3EynZPiSpQ

Similar to the KIA is the Reti Opening (1.Nf3).  The Reti can also provide you with flexible options in the opening...

https://en.wikipedia.org/wiki/R%C3%A9ti_Opening

https://www.youtube.com/watch?v=eLiB8U9Kf0U

https://www.youtube.com/watch?v=fmVehutWcAA

https://www.youtube.com/watch?v=qmOn8ZaLPX0

Otherwise you might discover some ideas here...

Chess Openings Resources for Beginners and Beyond...

https://www.chess.com/blog/RussBell/openings-resources-for-beginners-and-beyond

https://www.chess.com/article/view/has-the-king-s-indian-attack-been-forgotten
https://www.newinchess.com/media/wysiwyg/product_pdf/7277.pdf

Pretty well all of my "big games" have been with the Black pieces.

If you are winning with Black and failing with White, it sounds like you aren't truly understanding the openings you are playing, and are simply "out-memorizing" your current level opponent.  If you actually "understand" the openings you play, then you would be able to execute the White side of them as well.  I have a number of brilliancies as White in the same openings that I play as Black.

Case in point (as a player that religiously plays the French Defense as Black):  http://charlottechesscenter.blogspot.com/2020/02/the-french-connection-volume-31.html

So when you claim to understand the Slav and Caro-Kann (based on your 1...c6), do you REALLY understand it?  Or do you just memorize a line or two as Black?  If you REALLY understand it, then you should have zero problems with White against that.  Then it comes more an issue of understanding additional openings, like what to do against 1.e4 e5.

https://www.chess.com/article/view/how-to-understand-openings

https://www.chess.com/article/view/the-perfect-opening-for-the-lazy-student

https://www.chess.com/blog/2Bf41-0/3-reasons-why-everyone-should-play-london-system-pawn-structures

https://www.chess.com/blog/2Bf41-0/london-system-q-a

https://www.chess.com/article/view/should-you-play-openings-like-magnus-carlsen

Maybe Nc3 G3 Bg2 0-0 

First four moves by white

Kings indian attack setup

You can try it

And then open the bishop's diagonal with c4 

Followed by b3 

Bb2 and some knight and queen moves 

Maybe it will work

Perhaps it would be a good idea to start with Discovering Chess Openings, a book about opening principles.

"... For beginning players, [Discovering Chess Openings] will offer an opportunity to start out on the right foot and really get a feel for what is happening on the board. ..." - FM Carsten Hansen (2006)
https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf

I provided some of those links in order to help you consider the suggestions of others, but I think the main thing is that you should look at some sample games in order to see some attacking ideas. Here is one of your games that, I think, gives some idea of the problem.

A book like My First Chess Opening Repertoire for White
https://www.newinchess.com/media/wysiwyg/product_pdf/9033.pdf
https://chessbookreviews.wordpress.com/tag/vincent-moret/

has a bunch of games to look at, but opening books are not the only thing to consider. Here are some other reading possibilities that I often mention:
Simple Attacking Plans by Fred Wilson (2012)
https://web.archive.org/web/20140708090402/https://www.chesscafe.com/text/review874.pdf
https://dev.jeremysilman.com/shop/pc/Simple-Attacking-Plans-77p3731.htm
Logical Chess: Move by Move by Irving Chernev (1957)
https://web.archive.org/web/20140708104437/https://www.chesscafe.com/text/logichess.pdf
Winning Chess by Irving Chernev and Fred Reinfeld (1948)
https://web.archive.org/web/20140708093415/https://www.chesscafe.com/text/review919.pdf
Back to Basics: Tactics by Dan Heisman (2007)
https://web.archive.org/web/20140708233537/https://www.chesscafe.com/text/review585.pdf
https://www.chess.com/article/view/book-review-back-to-basics-tactics
https://static1.squarespace.com/static/5856bd64ff7c50433c3803db/t/5895fc0ca5790af7895297e4/1486224396755/btbtactics2excerpt.pdf
Getting back to openings, it might be worth some time to learn more about opening principles from Discovering Chess Openings by GM John Emms (2006).
https://web.archive.org/web/20140627114655/https://www.chesscafe.com/text/hansen91.pdf

I not trying to tell you to get all of them. I am just offering possibilities.

Perhaps, after looking at some illustrative games, you will notice some ideas that you will want to try.

If you like, you can make your own choice of one of your losses for others to look at.

Many beginners prefer black, they can't say why and think it is unusual, when the actual reason is  the choice of opening keeps them in their comfort zone. For example you play theCaro-Kann, you don't have to know the French,Sicilian or double King pawn positions, you can get a feel for that. The advantage of playing White really is not much until you play some strongercompetition.

Play a3

When you get white turn on high contrast mode.

So when you have W play 1 c6. Playing your normal positions a move up can't be bad. And most players will not know how to respond- they will be out of their own 'comfort zones' and think you have made a mistake they are obligated to punish.The best advice ever on openings for amateurs is do not look for the Grandmaster approved 'best' move, look for the move that gets you into the kind of positions you wish to play.