Some of the answers here are so useless - God, I hate the internet.
Anyway, I'll try to give you a more constructive one as you bothered to take the time to post and it's a thoughtful question.
You seem to have 2 dilemmas:
You disagree with wasting your time getting laid as it's not really constructive in any sense except for getting off for a few minutes and not worth the investment
You disagree with marriage, as humans are naturally polygamous and have trouble fighting their DNA and end up causing pain to women, who have been brought up in a society where their worth is based upon how faithful and monogamous they can get a man to be
I think they're both excellent points.
As to the first one - I kinda agree. I am a woman and I get lots and lots of offers off guys - I take good care of my appearance, A. to fit into society's standards as it makes life a lot easier, and B. attention makes me feel good about myself - having promiscuous sex doesn't. So I don't really have a lot of sex.
As to the second one - I have often wondered about whether I want to get married or not. For the same reasons you give. Humans are polygamous. Why waste my time worried about a guy and what he thinks of me, when his hormones want him to cheat regardless of what a good wife I am or how spicey I try to make our sex life. Why not just spend time investing in myself, a career, making a difference and getting money. It's not as if women can't do these things today.
However, it always comes back to the point of why we have these urges in the first place. To produce children. I would like to have kids one day, pass on all my knowledge and wisdom to them, and I never had a healthy family life - so I would like to start my own family in order to have a family and show my kids a decent parental figure.
If you don't wanna have kids - I'd say yeah: just masturbate. Better all round really.
But I do - so I will keep trying to find a guy who thinks the way I do, and who is either incredibly strong and self-controlling (I am personally, pretty good at controlling my animal DNA - didn't get with many "alpha males" that women have the same biological inclination towards, the way men do with multiple women, even though I got offers) or I'd consider taking the unfortunate step of letting a guy sow his wild oats when he was younger, on the proviso that if we got married/have kids he'd stop, but the first is a much more preferable option.
I think you're clearly not ready to settle down yet and you should just stay single and masturbate or have casual sex if you can (again, casual sex doesn't feel great for women - but as long as it's consensual it's their own fault and it feels infinitely less worse than being cheated on).
Don't be pressured by societal norms into getting married and having a family - and ensure you are clear to the women you date that that isn't on the cards if you don't want it to be.
If you do get ready to be a father, I'd try to control your urges, on the basis that true happiness is always based on self-discipline, and not on fulfilling our primitive instincts. People get primitive highs from all kinds of things including greed and fighting - but the more you think with your logical, modern brain - the more happy you'll be in the long run. I do believe stable 2-parent families are the best way to raise kids, and I think if this is your goal and you focus on it - you'll be better at keeping it in your pants.