What to study?
There's no magic formula, just work on your weak areas.
There's probably an aspect you find boring, or outright dislike. Attacks? Openings? Endgames? Tactics?
Or maybe something you know is difficult for you. Calculation? Visualization? Time management?
Whatever it is, you've probably been avoiding it because it's not something you like. If you focus on it, you'll improve... not just in that area, because knowledge in one area tends to complement other areas as well.
Only you can determine what you need to study. Analyze your games with brutal honesty and identify where your weaknesses are. Focus on those in your studies. Most of us (me included) want to study what we like and enjoy, but those are probably the areas where we are already pretty good. Chess improvement is hard...it takes honest evaluation of our play and determined effort to improve our weak areas.
One possible means of identifying weak areas is the book "Chess Exam and Training Guide" by IM Igor Khmelnitsky. I just received the book and haven't had a chance to go through it yet, but it contains a test consisting of 100 positions. After completing the test, you are rated in 12 different areas. The theory is that you can then focus your training efforts on the areas where you are weakest. I can't yet vouch for the approach, but it does sound reasonable and potentially very effective.
I looked over a few of your 3-days-per-move games (I felt that your 3-minute Blitz games wouldn't tell me much) and it looks to me like you still need to focus some effort on developing your tactical alertness. The games against cxpdleo and legan223 could have been won very quickly if you had been a bit more alert... you dropped a piece against legan223 and missed a chance to win material on move 6 (!) against cxpdleo.
"... This book is the first volume in a series of manuals designed for players who are building the foundations of their chess knowledge. The reader will receive the necessary basic knowledge in six areas of the game - tactcs, positional play, strategy, the calculation of variations, the opening and the endgame. ... To make the book entertaining and varied, I have mixed up these different areas, ..." - GM Artur Yusupov
That quote is from the first book in Yusupov's series.
To anyone thinking of working through the books, I would strongly suggest an examination of various online material to get an idea of what they are like. By the way, as I understand it, the official order is Build-1, Boost-1, Evolution-1, Exam-1, Build-2, Boost-2, etc.
http://www.qualitychess.co.uk/ebooks/Build-up-Your-Chess-1-exceprt.pdf
https://web.archive.org/web/20140708103321/http://www.chesscafe.com/text/review699.pdf
http://www.qualitychess.co.uk/ebooks/Build-up-your-chess-2-excerpt.pdf
http://www.qualitychess.co.uk/ebooks/Build-up-Your-Chess-3-exceprt.pdf
https://web.archive.org/web/20140708103659/http://www.chesscafe.com/text/review778.pdf
http://dev.jeremysilman.com/shop/pc/Boost-Your-Chess-1-77p3744.htm
http://www.qualitychess.co.uk/ebooks/Boost-Your-Chess-1-excerpt.pdf
http://dev.jeremysilman.com/shop/pc/Boost-Your-Chess-2-77p3745.htm
http://www.qualitychess.co.uk/ebooks/BoostYourChess2-excerpt.pdf
http://dev.jeremysilman.com/shop/pc/Boost-Your-Chess-3-77p3746.htm
http://www.qualitychess.co.uk/ebooks/BoostYourChess3.pdf
https://web.archive.org/web/20140708103149/http://www.chesscafe.com/text/review834.pdf
http://www.qualitychess.co.uk/ebooks/Chess-Evolution-1-excerpt.pdf
https://web.archive.org/web/20140708085817/http://www.chesscafe.com/text/review843.pdf
http://dev.jeremysilman.com/shop/pc/Chess-Evolution-2-77p3643.htm
http://www.qualitychess.co.uk/ebooks/Chess_Evolution_2-excerpt.pdf
http://dev.jeremysilman.com/shop/pc/Chess-Evolution-3-Mastery-77p3753.htm
http://www.qualitychess.co.uk/ebooks/Chess_Evolution_3-excerpt.pdf
http://www.qualitychess.co.uk/ebooks/QandAwithArturYusupovQualityChessAugust2013.pdf
https://www.qualitychess.co.uk/ebooks/Revision&Exam1-excerpt.pdf
"Fundamentals first, then Beyond the Basics and finally Mastery. Follow the colours!" - Yusupov