If I got varicocele from excessive masturbation and fatigue, can stopping masturbation cure it? Or other ways besides surgery? I can't afford it..

Not related. Varicoceles are due to incompetent venous valves between testis & vena cava. Not related to masturbation. Don't feel guilty about masturbation. Excessive masturbation can result in sore penis or some stinging when urinating that's all!
Not related. A varicocele does not result from masturbation, about 16 % of males have a varicocele. Varicoleles don't need treatment unless discomfort or infertility are present.
Just not true. Your varicocele has nothing to do with your enjoying yourself when you're by yourself. I'm sorry anyone told you otherwise. You should be proud of your adult male body. This is something that prepares you to be a husband and father. Think about something nice -- maybe the person you'll marry -- rather than internet trash. No need to fix the varicocele, or a free clinic may be able to help.