Are you able to retract your foreskin and properly clean the tip regularly?

not not really.I have a really tight foreskin.Do you think it has something to do with not cleaning it.I do shower once a day.

Are you able to actually retract your foreskin, clean it properly and dry it off?

The moisture that the foreskin can trap can be a breeding ground for germs and infection. It's really important to clean underneath it thoroughly and regularly.

The rash/sore you're experiencing could be a reaction to anything that is under your foreskin. It's not your fault that you have a tight foreskin and can't clean it. There are several foreskin stretching techniques you can try so that you can retract it without any pain or damage.

You can also consult a health professional about it if you're having difficulty.

Frequent masturbation itself won't harm you. That's probably not what's causing the irritation you're experiencing.
I hope this helps!