Re: number of times one can masterbate in a day.
Your body will tell you when you have masturbated too many times, with signs such as a sore penis, inflamed foreskin (use more lube), aching when erect, needing significantly more stimulus to erect and orgasm, taking much longer to ejaculate (if at all), less ejaculate, your arm will be sore and/or ache. You will probably identify at least a few of these, as will most guys!!!
We have all been there and done it and survived and have no problems stemming from this.