why do hands like this piss me off so much?

[waffle]

Villian is unknown but I'm beginning to suspect he's a bit of a LAG. I have also been folding a bunch recently.

Party Poker 3/6 Hold'em (6 max, 6 handed) converter

Preflop: Hero is CO with A[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/heart.gif[/img].
UTG calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, Button calls, <font color="#666666">1 fold</font>, BB calls, UTG calls.

Flop: (8.33 SB) J[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, <font color="#CC3333">UTG bets</font>, <font color="#CC3333">Hero raises</font>, Button folds, BB folds, <font color="#CC3333">UTG 3-bets</font>, Hero calls.

Turn: (7.16 BB) 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">UTG bets</font>, Hero calls.

River: (9.16 BB) T[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">UTG bets</font>, Hero calls.

Final Pot: 11.16 BB

After the 3bet I have to decide to peel or call down.. I decide he probably has either a Q, a T, a T and a pair, two pair, or maybe just a J or a 9. A set is pretty unlikely. I'll call down and fold to a 8 or a K.

Results in white below: <font color="#FFFFFF">
UTG has 9c 7c (flush, jack high).
Hero has Ac Jh (one pair, jacks).
Outcome: UTG wins 11.16 BB. </font>

I was just going to post this and ask the titular question, but I'll answer it, too. Why am I upset after this hand?

1. It upsets me that my opponent is unpredictable/adaptive enough to 3bet this flop with such a crap holding. He almost made me fold the best hand.

2. It upsets me that I chose a suboptimal strategy IN THIS CASE. Even though I should be thinking about how my strategy fares against his range of hands. (I probably didn't do too well there either, but I'm not good at making those kinds of analysis)

3. It upsets me that I put money in on the flop and turn with a decent equity edge and lost anyway, due to an erroneous notion of a certain hand "deserving" to win.

All in all, pretty poor attitudes to have. I don't deal with unpredictable opponents well. How can I improve my attitude, my thinking, and my play against unpredictable opponents?