Hi,
I totally understand how you feel, since I pretty much feel the same still, and would like to be more confident when flying, specially solo.
I usually go with a safety pilot who is much more experienced than me, and tbh, I really don't get the point of solo flying requirements or preference, since you never know when you might feel ill or when something may go wrong, and much better not to be alone in these cases obviously.... This part is the most tough for me.
I think what most helps is practice (like everything in life), good judgement, self-confidence and a "safety-first" attitude and behaviour.