My penis smells like fish?

actually, genitals that are not cleaned smell the same all around. The way I smell when I'm not clean is pretty much the same as a guy when he's not clean. So don't worry, it's probably just hygiene. I don't think it's possible to get a genital infection from oral sex, especially oral sex on a woman. You could get an infection in your mouth and that's about it, unless we're talking HIV, which wouldn't result in your symptoms and is really hard to catch from oral sex (1 in 10,000 with an infected partner, and that's oral sex on a man, not a woman).

It has a lot to do with what you are eating. Your diet causes you to smell a certain way so if your not eating healthy and a lot of junk food and not cleaning your self well is all why you smell like that. try using some baby powder down there after every shower just to keep it freshened up and like if your out and about and are sweating or doing something active where you know your sweating, have some baby wipes to whip it off after just to keep from any smell to happen.

By any chance are you uncircumcised?
If this is so maybe you should try cleaning yourself more properly.
Or maybe perhaps you have developed a yeast infection due
to not cleaning yourself thoroughly.

dude go wash your dick

Well wash it off. Certainly you understand the need and procedures personal hygiene. The smell is from seminal fluid left on your penis. So wash it off.

Alright. Might be several things. I think sperm itself also can smell like that. Have you had wet dreams, possibly? Or getting a hard-on looking at girls around you? In that case you might also have "leaked" pre-cum (no clue what the technical name is). If so, then just wash, and change your underwear. End of story.

If not, then I don't think it's normal. Smell normally comes from bacteria. Try anti-bacterial soap. If it doesn't help either, then you really only have the choice of living with it, or consulting a doctor.