Yes, It is necesary to study your games to find out what is the area you need to work on.
I recomend you to no play that many 5 minutes games, becouse they teach bad habits. Try playing longer games, and think more carefully the positions.
I notice some of your games you resign them just after you move, this is you relice you did a bad move and resign, if you get to fix this to find a blunder move before and not after you play it, just for this you will get to 1300s maybe more.
I don't know why this is hapening. Maybe you are not visualicing the moves and after you play them you see the consequence. Maybe it is just a matter of time presure and playing whatever instead timing out.
I think some of the other resignations where not lost positions. Maybe you are too easy to resign. For example this game:
http://www.chess.com/livechess/game.html?id=251983539
You could have take the rook with the king and win the game. As some other games you could had draw and still you resigned becouse you lost some material.
Still you need to find out if your problem is you need more time to think or it is visualization.
I registered today and found out that my rating is around 1200. I would like to raise it but simply playing doesn't seem to help. Are there any specific steps that I could take to reliably raise my rating to 1300?