Unusual Sensation In Urethra At The Top Of Penis. Having Skin Infection In Groin Area. Ejaculating Very Early Due To This Sensation. Advise?

Question: Hello, I want to share problem with you.
I am male, age 29 and physically fit.For last 9-10 years, I have some unusual sensation sort of thing in my urethra specifically at the top of the penis. I remember problem started when I went to college in Mumbai and because of humidity, I caught skin infection in the groin area. This infection was diagnosed at that time. But one more problem was there which I didn't discuss with dermatologist. There was some itching inside my urethra at the opening as well as 1-2 cm insides penis in relaxed state. Also, there was some skin colour change (slight whitish/pinkish around the opening). From my self examination, I figured it out that this problem was manly because of unhygienic conditions specifically I didn't wash and clear my penis after masturbation. From that point, I started to wash my penis and the problem intensity was reduced, but still today, I have some unusual sensation (you cannot call it itching) in that area.
Now here come the main part of the problem. From that instance, I figure out that whenever I masturbate and get engaged in love making with my gf ( I always have protected sex, so no case of STI), a clear transparent fluid leaks out from the penis.
This is manly precum. It seems because of that infection or anything else, I am not able to hold the precum and it flows out. Also that sensation causes me to ejaculate early and not able to hold for longer duration. The problem got intensified when I took some medicines for depression. I took for about 1-5 years and have stopped it now for about 3-4 months.Now, I am ejaculating very early and the semen quantity is very less, this is because of both that sensation and these medicines. During sex as well as masturbation, whenever that sensual part of urethra get rubbed, I cannot hold my ejaculation and ejaculate within a minute. Since, that sensation is at the top part of the penis, it will always get rubbed. I am totally distressed. Also, I don't feel itching during urination, But sometimes, after sex or masturbation, an intense pain (burning sensation) is felt inside the penis, lower abdomen and that feeling goes till the anus. It feels like I want to go for toilet or excretion. And the pain resides after some time. I went for my urine test and there was no infection detected. The sensation is like if I start rubbing the penis on that part, some fluid (precum) will definitely come out. Mainly, I am not able to hold my ejaculation because of this sensation.

Are there any specific test for clinical evaluation. One thing I want to say is that if i masturbate without touching that part, I can perform well. Since that part is at the top, by no means, I can avoid touching that part. Since the problem is about 9-10 years old, will that sensation go after medication. Is there any physical damage to urethra such as cut or something else. Is it possible that infection can last so long and causing these symptoms.

What are general antibiotics given for urethral infections ? Is there any ointment that can be applied....