Anger management...anger management...
I do know how you feel, I once got a cat because someone told me they lower the blood pressure. Well, after the stupid clawed furniture and chewed everything, and yowling all the time, my blood pressure was through the roof. I decided to go into fish. (I wasn't mature enough for a cat.)
So the fish started to die. (I wasn't mature enough for fish.) All except for the betta that was swimming in about 2 cups of water in a little bettahex (I KNOW, I KNOW, it eats me up inside. I have no idea how that fish survived 3 years with never a sign of fin rot or anything.)
Now that I have matured, done some research and decided what it is I want, there are fish everywhere, tanks on every flat surface, and no one has died in months.
Advice:
Learn about what went wrong.
Decide if you are willing to do it right.
If no, have a yard sale or put an ad in the paper and sell your tank and stuff.
If yes, start doing it right. And take it slow. You will get what you want.