Endgames

I had a game where I was winning and I blundered a bit in the middle where I could have lost a rook, but luckily my opponent didn't find it. The match itself had way too many ups and downs and this was my most difficult match. But there was a time in the match where I was two pawns up, and eventually a knight up but I messed up on my endgame calculation and drew(but a very long match). Any help in reviewing this endgame because I felt like I couldn't progress in the endgame. 

..

The endgame above is hard to win

There's many moments I'm sure, but which color are you? I looked at move 100...Kb3 and 101. Qe4 looks like a way for white to win.

This video of mine may help

Man, my brain hasn't even been able to evolved to understand how this happened, y'all are awesome.