I feel like I have wasted any potential I might have had.
What do you mean by that?
I was okay at what I did, and I enjoyed it, but now it just pisses me off
You shouldn't waste your potential, and you should usually work on improving yourself.  Maybe you've just hit a rough patch.  However, if you are really unhappy in your current line of work, then it's fine to try something new.
Yeah, I guess...
I think that this feeling will soon pass, so I would advise that you take a short break.  If you have vacation time saved up, do something fun, and when you come back, you might realize that your work is enjoyable again.  If people have missed you, then you'll know that your work is appreciated and worthwhile.