I feel so lost and stuck and I don't know what to do?

I feel like this sometimes too. But I was able to get through it. Maybe you're just not as strong, and that's understandable. First of all, if you're unhappy with church, just leave it. I'm non-religious, and if you hate "god", then don't believe in him. However, the shyness if something you can change. I know it's more difficult for girls to be less shy, but you just have to open up. Find a fun hobby, get a boyfriend, and there are many other things to do. I've gotten through this thought. I really hope you do too.