Is There A Short Term Or Long Term Problem With Masturbating 3-4 Times Daily ?

I'd like to know if I could have any problem in the future if I masturbate 3-4 times on a daily basis.

When I masturbate I don't do it ALL times watching porn, it's more like 50/50 between just PORN and IMAGINATION, I try to do it fast so I don't take up much of my time, when I want to finish.

Here's another concern I am having, MOST of the time I do it, I don't get any sperm out, sometimes just a little bit, just some small drops of sperm get out, I think that's because I rush into masturbating (4-6 minutes avg.) .

The reason I think that is because when I take much more time to masturbate (20-40 minutes avg.) I really feel much more as when having sex and sperm COMES OUT pretty rapidly and in large quantity, just like those good old times ( I'm not virgin, have had around 6 girls, each with MORE than 2 sex encounters but LESS than 5 sex encounters )

I do not want to date a girl, I do not want to have any experience anymore with any girl for NOW. The reason why is because I am so focused right now with my future that I can't be spending time with another person, the second I finish posting this I will be studying or reading another financial book.

To make my concerns more understandable will break them down into these questions:

Is there any (Physical) problem with masturbating 3-4 times daily?

Is there any reason to be worried when I'm not getting sperm out when these masturbation that last 4-6 minutes avg.  occur?

I turned 17 years old on 5th march and in each and every single sexual encounter I have had I used protection, I am responsible when it comes to sex.

Another thing I want to add is that I can control the amount of masturbation and porn I experience, I have done it twice in the last 3 months, I have put in an amount of weeks where I will not watch porn nor masturbate under any circumstance and I have accomplished both of those goals, so combined were 8 weeks where I avoid them.

Masturbation is not making me mentally ill, I still in control of my thoughts,I do the masturbation thing though because I use it as a method of reward myself when I finish certain things, the more I get done, the more chances I get to masturbate, but 4 times is the limit on a day, no matter what I get done.

I am giving all these details just so any specialist out there can give a more accurate answer

Thanks for your time.