Hey I am 23. I was just trying to have sex without a condom for the first time with my girlfriend. I am an uncircumcised dude. My foreskin does not go all the back. After copulation my foreskin is stuck behind my mushroom head. What should I do?
The biggest problem is spiritual, not physical. Sex before marriage is a sin, called fornication, because it causes harm to relationships and people. "Marriage is to be held in honor among all, and the marriage bed is to be undefiled; for fornicators and adulterers God will judge" (Hebrews 13:4). See: http://lavistachurchofchrist.org/LVarticles/MarriagesGlue.html
The end of your foreskin is too tight, which is called phimosis. When the foreskin is stuck behind the glans, it is called paraphimosis. Correcting the immediate problem is not difficult if your foreskin has not swollen excessively. The illustration shows how to get the foreskin back into place. It should be done when you are flaccid. If the swelling is too much to get the foreskin to go back into place, you will need to see your doctor. It should not be put off. See also: I pushed my foreskin behind my glans, but now it is really painful.
For long term correction, so it doesn't happen again, see: I can pull my foreskin right back, but when it is pulled back it is really tight and I don't know if it is normal or if if I need to be circumcised.