I would tell myself not to be so concerned with what others think of me. I spent a good deal of time trying to make family members happy and proud. I wish I'd had the confidence to believe in who I was and who I wanted to be.
A good cover is an enormous part of the process. If a cover draws me in, I want to know more about the book. Title is super important also, but I think more forgiving than the cover.
I absolutely have drawn on real situations and even a few people (though not by name, more of their vibe). Writing is a wonderful way to heal trauma, by releasing it into a book.
Eat well, take care of your body and your mind will respond better. Write, write, write! Even if what you have written is not your best work, you can edit and improve upon it, but writing is a muscle and it needs to be worked to function at its best.