Eating fish is making me sick.

Hi I’m 19 weeks pregnant and I do not like to eat fish! Even fish oil is making me nauseous. I know that its good for the baby thus I force myself to eat fish or take the fish oil capsule but the result after consumption was very bad. I will either have a very bad indigestion or nauseous. This is my 3rd pregnancy and I’ve been like this since my first trimester. I was not like this at all during my 1st and 2nd baby. Im worried that I’m not giving enough nutrients for my 3rd one. Anybody experiencing/experienced the same issue with me?