22 with pain on penis head, erectile dysfunction, and scared

[JACOB P.]

About 3 months ago, I had safe sex with this chick and I think my penis
was injured in the act. since then, my dick hasn't been the same at all. I
started noticing this weird pain on the head of my penis and it's very
concentrated. it's mostly under the tip of the penis close to the hole and easy
to bother. At first i thought it was nothing, but the pain still hasnt left.
When i masturbate, attempt to have sex, or when getting a bj, the head hurts
even til the next day and once the pain is "activated" even putting on underwear
can bother it. But my biggest worry are my erections. When the pain first
started, i still had normal erections like during the first week or so. But as
time went by and the pain got greater, my erections got significantly weaker.
Like i haven't been able to get a proper boner in months. It really sucks. When
i get horny all i get is a flacid penis. Even when i masturbate, it's like half
the strength of what my boners where and it's hard to maintain. Often when i pee, i feel this weird sting/slightly painful feeling on the inside that i've never felt before. like i can feel the pee traveling and
it's bothersome. I once felt the sting when ejaculating and i sometimes feel it
without needing to pee. I got std tested and found i had chlamydia, which i got
meds for. I also went to a urologist and said i had non-specific urethitist from
the chlamydia and gave me doxycycline 100mg. He said the erectile dysfunction
was all in my head and there was no way a 22 year old could have problems with
his erection unless he has like brain cancer or something. My libido has
plummeted as well. I finished the meds a couple of days ago. Have noticed the penis head pain has gone down a bit. However, now i'm feeling this weird feeling inside me. The best way i can describe is like you know when you're driving down a hill really fast and you feel that funny pressure on your bottom area. yeah, the feeling is pretty analogous to that albeit not nearly as strong. that feeling might be my imagination though. Also, for the past 4 days i've been having a bloody stool if that means anything. What do you guys think?