What are some good self help books?

Hello, I (28m) am a very hard working, caring individual. I run my own diesel repair business and even tho I have a good life and I’m a caring person I’m not happy. I have some emotional issues, communication issues when it comes to communicating with my partner. And underneath the facade I’m unhappy. Love of my life just left me even tho I thought I was a good partner but I think it’s because of my emotional failings. I want to grow and be a happy, and well rounded man. I have no health insurance since I just started my business so I can’t afford therapy. What are some good books to help me improve myself become the man I want to be? Thank you in advance.