why can't I get my head around 1.d4, 2.c4

I wonder if anyone else has this problem

otb I play all the other systems with reasonable results with (I prefer a more closed strategic game) - London, Tromp, Torre, Colle but I want to push myself and play 1.d4, 2.c4.

the problem, after..

1.d4 d5 2.c4 dxc4 3.e4 Nf6 4.e5

or

1.d4 d5 2.c4 c6 3.Nc3 dxc4 4.e4 b5 5.a4

or

1.d4 d5 2.c4 e6 3.Nc3 dxc4 4.e4 a6 5.a4 Bb4 6.Be3

it feels like i'm entering in a game/position I don't really won't to play (or understand that well).

It feels like after 1.d4 d5 2.c4 black getting everything he wants..

youll do better with stuff you feel comfortable playing

I had that problem, with pretty poor results OTB as white, but after switching back to tromp ive done much better.

These can be some wild lines, so I understand you not wanting to get into them.

What I like to do is get to the first position where at that point you're uncomfortalbe... especially where you're saying to yourself "black has everything he wants."

Clearly define for yourself (or even write down) the advantageous you think black has and/or the problems white has.  It's useful to include a few short variations IMO.

Then put this position into a computer, let the computer be white and you can try out all these ideas / reasons black has a comfortable game.  Maybe G/20.  One by one the computer can show you why it won't be so easy.

Then modify your list.  Maybe you said "black gets lots of space on the Q-side and hinders smooth development for me"  and after you play black vs the computer you may add "in the end those pawns became targets / weak" or something like this.

Once you get a feel for why certain trumps aren't as powerful as they may seem, you can play over some real games (GM games) and see these ideas battle each other out.

If in the GM game you think "that makes no sense, why not punish white by _____" then again clearly define why you think it's better (variations and all) and test your idea vs a computer.

This is what I like to do anyway, it can be fun (but also time consuming ;)

I think 3. Nf3 is much easier to play than 3. e4, and after 3...Nf6, then 4. e3, after which you'll get back the pawn back on the next move and have a fine game:

This is Watson's recommendation in his recent strategic repertoire book for White.

 I don't like any of the lines you play.

As other people have said, generally in the c6 lines you should prefer Nf3 over Nc3.

1.d4 d5 2.c4 dxc4 3.e3 is my choice, as 3...b5 is almost losing now (4.a4 c6 5.axb5 axb5?? 6.Qf3 1-0)

1.d4 d5 2.c4 c6 3.Nf3 and Black doesn't have any weird lines with taking on c4, 3...e6 is well-enough met by 4.e3 or 4.Qc2.

1.d4 d5 2.c4 e6 3.Nc3 dxc4 is extremely rare. 4.e4 a6 5.Bxc4 b5 6.Bb3 is a nice comfortable White advantage.

Based on the various suggestions, it seems the OP was consistently missing Nf3.  There is nothing wrong with the move order 1 d4 d5 2 Nf3 and then 3 c4 if it fits.

Thanks for the responses people.

I think I always find that after c4 the rook etc is vunerable on the b2 - g7 diagonal - especially against any setup with black Bishop on g7.

i'll look at 2.Nf3