First of all, the correct spelling is masturbate.
Second, blow-jobs are very low-intensity. So most men cannot get off on it alone. Hand-jobs may also be considered a low-intensity activity, but I think that we’re just used to our own hands. It takes my girlfriend at least 30min to get me off with her hands and mouth. It can be done but it needs dedication. It could be a combination of her not knowing what will get you off and also you not being responsive to the stimulus.
Personally, I’ve had a lot of fulfillment ballooning since it increases sensitivity everywhere (nipples, balls, perineum, etc) instead of just the glans. Do a search for it. When you get more sensitive and she gets more experienced, it’ll get better.
As for now, don’t worry about coming and maybe lay off the masturbating. Not masturbating will increase your sensitivity and not forcing orgasm will help you achieve it. But take note that I don’t think you’re over-masturbating. I just think it’ll help if you lay off. Let me know if you want more detail or if this wasn’t the answer you’re looking for.
Technique-wise, there are many instruction manuals online that she could read (or you could read and suggest she try). Try some at literotica.com (Top How To stories on Literotica.com for all time) P.S. Mods, is this an ok link? Also, this is a VERY good one:
http://prettydu mbthings.typepa … ng_for_sem.html
Make sure you brush up on your oral skills too!
Personally for me, it’s better if she uses both hands since there are many more things you can do with two hands. Two hands and a mouth are priceless.