I don't really enjoy playing chess anymore.

You already identified your weakness. You don't know what to do if you can't find a tactic, so you need to study positional concepts/middle game plans in chess.

In examining your most recent loss, you didn't blunder right away really but you got way too aggressive before the position called for it and you had developed. In fact your opponent had a marginally better position before you even began your attack. You let him create a weakness on c3 and then plant his knight in the center targeting that weakness. Then you proceeded to attack along the b file where there was no attack. Then you played a move that brought another attacker to your weak pawns.

Make sure to develop fully, try to avoid pawn weakness but if you can't then certainly don't make it easy for your opponent to pile on them

He also gave you a chance to remove your weakness on Nd7 where c5 forced your win of the b file or he had to trade or move to an inferior position. From there, be2, castle, maybe even knight to the middle of the board and f3 eventually.

In your game vs chessman you were completely winning. Computer evaluated as +3 and then you annihilated your position because you weren't thinking positionally.

Double :/

Chess can be cruel.  Somedays it is the best thing ever and you could happily play 100 games all afternoon, winning some, losing some, neither really mattering.  Other times, though, eating liquid sludge seems more appealing than staring at the board for another moment.

I heartily recommend taking a break from chess, as Monie49 suggested.  You are not a professional, so you have no obligation.  Take time off.  It might be days, weeks or months, but you'll come back refreshed.  And if you never come back, well, then you likely found something better than chess to occupy your time.

I've taken several breaks from chess, sometimes lasting years.  It's natural.  Treat it like a vacation.

Lastly, the first step in real improvement starts with realizing just how much you don't know.  Judging by your indecision, you are starting to grasp the depth of chess, and it can be scary.  If you decide to keep going, you will likely soon break through your plateau, though it will take work.  Also, that feeling of indecision never really goes away.  I still stare at the board, wondering what the heck I'm supposed to do.  I do it better than a few years ago, but it's far from easy.  Chess is not an easy game, which is its main attraction and main disadvantage.  

If it has stopped being fun then maybe you are taking it too seriously. Just try and enjoy your games and if that doesn't work, maybe take a break for a while.

Enjoy your games, it looks like you are taking it too seriously.

Thanks for most of all the comments and suggestions.

wow I did not realize I had all of these mostly good suggestions. Thanks again.

I will never play chess again.  I've  grown to hate the game.