I agree that 6 times a day is excessive. Beyond the excessive aspect, masturbation is actually very good for you...it releases "feel good" chemicals. It's a normal thing to do, but like anything else, in excess, it can cause problems.
Whether or not your excessive masturbation for years has contributed to your anxiety would be very hard to tell. I think talking to a mental health provider is a good move. I'm sure it's a little embarrassing to talk about that, but these are professionals, they have heard it all....so try not to be afraid to open up. Being assessed by a professional will involve more than just talk of the masturbation.
Regardless of the cause, your symptoms are causing you enough distress in your life that it's time to do something about it.
Good luck, keep us posted.
Masturbating six times a day is excessive, but I wonder if this has anything to do with your anxiety. It might depend upon how long ago you stopped. Sexual stimulation and orgasms do produce a kind of high with its extreme pleasure, so if you suddenly stopped, then you could feel the let-down effect. If your anxiety does not subside fairly soon, it would be good to see a doctor who could delve into this.