The foreskin on my penis is very red and irritated, and i sometimes feel pain in the head of the penis, my foreskin is not tight. what is this?

Still...: Without direct inspection, it's hard to firmly state what it's; but the most common condition is still long-foreskin-related inflammation / yeast infection. So, keep the glans penis and foreskin clean ; dry after washed with tap water ; apply topical cream thinly with the ingredients of steroid and anti-fungus drugs. If not improved as expected in 1-2 wks, see urologist for possible circumcision.