I am 30, have not had any intercourse, and masturbate frequently. Please advise me how many times a week is healthy?

Masturbation is healthy unless it interferes with other areas of your life. For example, if the reason you have not had intercourse is because you are married to your VCR then it's unhealthy. Physically speaking, the only way that masturbation becomes unhealthy is if you are rubbing the skin off your penis. Aside from that you can do it as often as you like!