I relate to this heavily. There's lots of reasons why you might be stuck in this loop, but for me, it's because I'm a perfectionist. If you're like me, you have to accept that you're going to be bad at whatever it is you're wanting to do. You're going to suck, and that's a good thing because you can't be good at something unless you get through being bad at it. If you were given Gifted and Talented status as a child, you were probably deprived of this lesson and will need to learn it now. After you've acquired the cheapest and most basic version of whatever materials are needed, make the next item on your to-do list some version "suck at doing the thing".