Weird problem when having sex!?

Hello , I am really worried and trying to find out what is wrong with me. I had sex 2 days ago (its my 2nd partner --> 2nd time having sex in my life , im 21 btw) and I find out that it's the 2nd time I cannot cum / finish myself when having sex. I can only do it if i jerk off , otherwise I just cannot. I had sex 2 hours (till i started feeling pain in my penis and was forced to stop it and finish with jerking) I thought its the partner but I had sex with a different girl now and same thing happened again. Is it because I've watched TOO much porn when i was a teenager and masturbated VERY often + I've always thought the feeling of sex is different and much better (cause in porn you know its all overreacting and it created WRONG thoughts to me about how sex feels like). Is this normal? What's the reason for it? I wasn't worried if you think that's the reason , im not taking any medications , im not smoking , drinking , im having kinda healthy life (eating a lot of protein daily) I really cant understand what is wrong with me.

Almost all young men masturbate a lot, but don't have problems finishing during sex (unless it's finishing too soon).  If it's your first couple of times, then it could be a form of stage fright, and it may be very different for you the next time.

Some questions though - how often do you normally masturbate, how long does it take, and how do you actually do it?  Are you circumcised?

Im not circumcised , I used to masturbate almost every day (several times a day sometimes) and I were able to control it. When I had sex now I haven't been masturbating for a week.

Masturbating almost every day isn't unusual for a man aged 21.  When I discussed with some friends at school at age 17 or 18, one one out of seven didn't masturbate at all, and the other six did it between three times a day and three times a week (the three times a day lad seemed very surprised that everyone wasn't doing it that often).

If you'd abstained for a week before having sex for the second time ever, I'm surprised you could last longer than a minute or two.  Porn obviously isn't real, but most people do find sex very enjoyable, and a lot better than masturbating.  I'd have thought the problem might be psychological unless you have an unusual way of masturbating.  How long would you typically take to come when masturbating, and do you just use your hand?

Once again , I've been masturbating so much that I am able to control it , I can masturbate 1-2 hours (i've done it at nights but not NONSTOP i mean most of the time. And usually i do it fast and rough and I think I've lost my sensitivity in my penis cause of that + wrong expectations about how sex feels like because of porn and I was kinda disappointed i think. I had a feeling (not huge or what i expected , it was nice but not SO good as i thought it is) and that feeling was less better than my masturbation and that's why i couldnt finish myself I think. Only by jerking off at the end

I never used to masturbate for that long unless I came 2 or rarely 3 times.  We didn't have the internet 30 years ago though.

It's unusual for a man your age who'd abstained for a week to have problems being able to have an orgasm having sex.  It may well just fix itself next time whatever you do or don't do between now and then.  If you're worried though, my suggestions would be:

1) don't masturbate for as long.  Maybe 30 minutes max before ejaculating.

2) don't be as rough when you do it.

3) Think about getting a Fleshlight.  I've never used one, but it's supposed to feel a lot closer to having sex than regular masturbation.

4) don't worry

You could also try googling these:

"delayed ejaculation"

"anejaculation"

"man cannot ejaculate during intercourse".

You're not alone.  It seems to be a lot more common that I'd realised.