Oh, and just to add to Val's point. I've been keeping fish for 12 years. Some types and set-ups I've had perfected and have learned about as much as I need to when it comes to setting this type up. But if I were to throw myself into, say, brackish tanks, larger cichlid tanks, strict biotopes or monster fish tanks, I'd be totally out of my depth, as I would be with very sensitive fish. My next set-up will be difficult because, along with it being the smallest tank I've ever dealt with, I'll be keeping a bunch of fish and inverts I've never had experience with. We all end up out of our depths at some point, even those of us with more experience and success.
Part of fishkeeping is learning to do things properly, one step at a time, and what personally frustrates me is you don't just step back and think "what did I do wrong, how can I improve it", you just give up and start again and throw yourself into new projects constantly. You've really done no "working your way up" like most of us do, you've made the same mistakes and not learned from them, and that's when it becomes very very hard for people to advise you.