i keep blundering in the opening

so ever since i hit 1100, i am blundering basically every game in the opening. i dont know when to attack the center. i always end up losing an exchange or ending up in a bad position. someone please help me.

The answer to when to attack the center is "immediately". Do you have an opening system? Maybe share a representative game of yours for us to look at.

starting with the exchange on move #8 i lose a pawn in this exchange somehow....

i am black

OK, so at 1100 you're not going to be facing much opening theory. I don't play e4 and hate the Sicilian, so I don't know how much of this is memorized.

But! Two general points, that apply to you and many others. First, you blow up the position with d5 before all your pieces are activated. The bishop and both rooks could be helping.

Second, your "developed" pieces moved once and then sat, unless they were capturing something. They could be working to better squares.

So- patience before you go for something like d5. Even if you haven't worked out all the consequences of such a move, you have a better chance of it working out well if you have all your pieces protecting each other.

Also, I must point out that the specific blunder here was Bxe5. An earlier Re8 would have solved that. Active pieces have the magical property of making the tactics work for you.

so if i activated my rook to e file before blowing it up i could have survived that exchange equally?

what about my light squared bishop and my other rook? they are hard to activate in such opening positions........

There's nothing wrong with your 8th move. In fact, I prefer Black after 8. ... d5.

Your reply to 10. e5 should have been 10. ... Nd7, though. You can always meet 11. Nxd5 with Ndxe5.

Around 2010, IM John Watson wrote, "... For players with very limited experience, ... the Sicilian Defence ... normally leaves you with little room to manoeuvre and is best left until your positional skills develop. ... I'm still not excited about my students playing the Sicilian Defence at [the stage where they have a moderate level of experience and some opening competence], because it almost always means playing with less space and development, and in some cases with exotic and not particularly instructive pawn-structures. ... if you're taking the Sicilian up at [say, 1700 Elo and above], you should put in a lot of serious study time, as well as commit to playing it for a few years. ..."
In 2014, Pete Tamburro wrote, "... You will see [in Openings for Amateurs] the reply to 1.e4 to be the great reply of the open games with 1...e5. The Sicilian Dragon is presented as an alternative. ... I have found that scholastic players take to the Sicilian Dragon very quickly. ... A cautionary note: the Dragon is good at club level, but as you start facing better players you're going to find yourself memorizing tons of lines and the latest analysis, ... From my experience with coaching players below 1800, you won't need to do that too much. ..."

All openings have specific pieces that are troublesome to develop. But, it still has to be done. There are only two ways for a bishop to develop, so  if it gets blocked in on the long side it should be attempting to fianchetto. The other rook would then be free to do something- perhaps to take the queen's place, so the queen can activate further?

As to the specific position, yes- look at 14.Nxe5. That bishop was undefended. If you could have replied with Rxe5, you'd have been fine.

Your problem here isn't really the opening. It's missing a tactic, and your comments suggest you don't really understand why. If you had captured the e5 pawn with the knight at move 12 instead of the bishop, you would have been OK as far as I can see. But you took with the bishop, which was defended by the knight, which could be exchanged off, dropping the bishop. 

Everyone here is correct in saying you missed a tactic. Perhaps it has something to do with the other posters here being daily players- they've got time to work everything out. But 'seeing every tactic' isn't a reasonable goal for an 1100 playing blitz/bullet. 

If you've ever watched, say, Hikaru stream, he often says "Oops, I blundered X move", only to later be like, "Wait, no! I've got Y response. That's lucky!" Let me tell you- that ain't luck. That's having his pieces in good, active squares (and also being a tactical master). 

Should you study tactics? If you want to seriously train, sure. But if you just want to play games where you get reasonable middlegames, just activate your pieces.