Get mad at myself

When I am avoiding doing something that I know I need to do to achieve my goal and feel like it’s too hard and I need help, I get mad at myself for “not supporting myself.” I know that, for example, in the fitness area, hiring a personal trainer to “support” me in reaching my goal seems like a good idea, but I want to do it on my own. I want to prove to myself that I CAN do it by myself. This model leads not to support myself as a result.

What thoughts can I think to feel supported and achieve my goals by myself?