Way to nervous to do anything - help!!

So I’ve never had sex (I’m 18) and I’ve only ever given head once before but ik I wasn’t very good at it and tbh I’m so scared to try to do it again with any guy just because I honestly don’t know what I’m doing and I’m scared to do it wrong or in a way that doesn’t feel good? Idk if part of that is confidence issues or just the fact that I’m inexperienced but does anyone have any tips on how I can overcome it and stop being so scared to do it? I feel bad when guys will do stuff to me and then I don’t do anything back because I feel weird & nervous. Help pleaseeee!!!