This is a tough issue for many people, although it never really was to me, but I will offer some advice anyways:

1. Change how you evaluate yourself

When you're starting out, don't judge your progress or prowess by how much money you make. Seriously, just forget about it. Your ONLY concern is not making money, but rather making the right play each time; improving your poker.

Take each hand in a vaccum, and ask yourself not whether you CAN make money by calling/raising, but rather if you called/raised/bet 100,000 times in that spot, against the same opponents, you'd make money overall. In your example, you 3-bet when you know you're beat and that the other person will call. This is just spewing chips, hoping that this is the 1/100 change a reraise will fold a better hand.

Your reason for making that play is because it CAN work, and you're evaluating yourself based on the wrong metric, money. In your mind if you fold, you lose, if you bet, you MAY win. Winning poker has two components, betting when you have the best of it, but also NOT LOSING when you obviously have the worst of it. Any person/personality can do the first, it comes naturally. It takes a disciplined mind-set that drops the results-oriented kick, and makes the RIGHT play rather than the only one that can make them money on that particular hand. Most times the right play is to fold and lose less money. And then when you're obviously ahead, jam the pot and cash out bigger than you lose when you're behind.

Starting out, if you have to think about calling a raise, don't. Preflop, if you have to think about calling, fold.
On the flop, if you have to think about calling, fold.
On the turn/river, if you're thinking (rationally) about calling one bet, do.

Those are guidlines, in reality, use pot-odds and stick with it. Again, your goal should be making the right play, not the one that has the possibility to make you money. Make the play that would make you rich if you made the same play a million times, not the one that would bankrupt you.

2. If you don't have poker tracker, download it and try it. Even after the trial hands, post your stats. Odds are even at that point you'll see glaring holes in your game, or we will if it's that bad.

3. Winning low limit players play 15-25% of their hands. You should too, maybe even less sincee you like to be aggressive. Start by decreasing the number of hands you play (e.g. top 20%). It's tough to do, but it's another way to hold your tilt in check. Make a guideline, and stick with it thick and thin. You should be doing this on all streets, not just preflop, but it's easier to start here. Then over time, post your hand histories, not for plays in which you had monsters or got sucked out on, but any play where you didn't know what the RIGHT play was, win or lose the hand. We'll give you advice, and then you'll adjust your guidelines.

4. I can't stress enough, change how you evaluate yourself as a poker player. Not on how many pots or plays you win money with, but on how many plays/pots you make the correct descision for your game, your competition, your position, the board texture, and then your cards. If you're not thinking of these things every hand, you need to start posting and reading posts, to look at other people's thought processes in making the right call. Your goal is not making money, it is becoming the best, most consistent poker playing machine you can be. The money will come.

5. Everyone has bad luck. Poker has a huge luck component, and part of the skill is managing that luck, which means holding steady to the right plays when your luck is down. The best players in the world suffer huge up and down swings, but they don't give on themeselves or change their game when the downswings occur. You shouldn't either.

6. Bad beats happen to good people. When it happens to you, just laugh it off knowing you made the correct play, and that over time you will take the fish's money. After all, were it not for the river, there'd be no fish.

7. All of these things require that you never play with money you can't afford to lose. Look at your first deposits as both entertainment fees and training fees. Honestly, you should be able to see all of your deposits that way. If you can't, you shouldn't be playing. Needing money back is a direct conflict of interest to playing correctly. Play right, post hands, improve your strategy, the money part will take care of itself.

Good luck