Last week I had a swim lesson to improve my crawl and the instructor said that she could see me smiling under the water. Which was true. I was so happy to finally get my breathing in order, but now need to practice to really get to grips with it. I believed I could do it. Just needed some help (thanks @Rninecoaching - Sam).
Last night a lady came to me as her confidence had gone and she'd decided she couldn't get down to the floor, or more importantly get up. She was also worried about putting weight on a painful knee. By the end of the session she found she could get down plus up. She realised that lots of things she thought she couldn't do were in her head and she like me had a smile on her face.
If you struggle with things don't stop doing them. Believe you can do them. If not the full move, then maybe part of it and build up. Movement is physical, but also mental too.