Developed an allergy to my cat???

I’ve had cats my entire life growing up and now I have a 3 year old kitty who is super affectionate and loving, I’ve always been totally fine and never had issues with cats but I’m now around 18 weeks pregnant and my cat makes my eyes stream and my nose run like crazy and my throat so so itchy, I’ve never had anything like this with him so it’s very new. I’ve been changing his blankets every day and hoovering the house every morning but my nose and my eyes are so so irritated all of the time, I’ve gone through so much tissue paper blowing my nose and sneezing the last few weeks. Has anyone had anything similar to this? What did you do? Obviously getting rid of him is not an option I love him to bits and this isn’t his fault. How did you deal with it? Or how would you deal with it?