I’m so scared😢

Are you always suppose to feel excited and or get “butterflies” in a relationship..? I’ve been with my boyfriend for 4 years I love him so much, he’s my bestfriend I’m so comfortable around him I can be myself, I can’t picture me without him when I think about breaking up I want to cry😢 I was just recently diagnosed with generalized anxiety disorder idk if that has anything to do with it. But the thoughts “your not in love with him anymore” and “your forcing yourself to stay” somehow popped into my head out of nowhere about a month ago it makes me so upset I can’t stop crying they won’t g away, I want things to go back to normal I never once doubted my love for him ever before it’s killing me because I know I want to be with him.. I do what to do. I keep researching online I know it’s bad but I can’t help it I’ll feel relief for a minute but then they’ll come back or I’ll see a post that says something like “if your having doubts you shouldn’t be together” “if you lose the spark your not in love with them anymore” And I freak and start to cry, it’s scaring me so much Idk what to do.