Is it normal to suffocate after showering?

No.

That's not normal. Nearly passing out and shaking is a sign of low blood pressure. However, those symptoms can indicate many different conditions. I would strongly suggest seeing a doctor. Also, please add a normal/not normal if you're asking if it's normal.

a lot of shampoo and soap has added hydrocarbons and hydrocarbon additives. How do you do with walking down a soap isle in a grocery store. do you get tightness in the chest and almost pass out?

I've never heard of steam causing suffocation before, I thought steam can clear your air passageways. But, like a couple other commenters mentioned, a shower that's too hot increases body temperature, which then can raise blood pressure, and your blood pressure shooting up too high can cause shortness of breath. But that usually only happens if you already have blood pressure problems. You need to see your doctor about blood pressure meds, a healthier diet, and weight loss if you're overweight. Are you a heavy drinker? That can raise blood pressure too.

hydrate before showering. And make sure you ate too. If it continues don't shower with hot water

Yes, install a n exhaust fan in your bathroom

I have two questions for you. One, do you take hot showers, and two, do you have high blood pressure? I have a similar problem myself.

I have a friend who suffocate after shower. Its normal, But shaking looks serious, you gotta see a doctor if it happens everytime.