Is it okay to masturbate with phimosis? i want to feel the pleasure but it feels pain whenever i try to retract my foreskin. should i get a surgery ?

Evaluation needed: You can live your life as you wish. If this activity gives you pain you should seek an evaluation by a urologist. They can verify what problem exists and explain the options you have to deal with it. Surgery is an option but what is done can vary from a simple release to more involved total circumcision. Do not assume that is your only option.

Yes: This is a healthy part of growing up. Think about something nice -- maybe that one special person that you'll marry and be with through your life -- rather than internet trash. If your phimosis is giving you pain like this, it's time to see about getting treated without delay. In the meantime, explore various grips and lubricants that may be most comfortable.