Am I overreacting, also, AITAO? 29m engaged last year. Big time cold feet.

Me and my spouse recently go engaged sometime last year. Long story short, a big point of conflict has always been whether we would have children. We’ve been together for about 9 years. I love her dearly, couldn’t imagine living without her. She doesn’t want children, but I’ve always kind of been on the fence. I proposed last year after healing through some traumatic losses, she supported me whole heartedly, every step of the way and I couldn’t be more grateful. Problem is, I’ve had a large change, I want children. Pretty bad, and the thought of living my life without them has been enough to bring me to tears or depressed. She knows I want children now but she’s very adamant about not wanting them. I just don’t know what to do. I’ve got no one to discuss this within my family since my family is more or less non existent. Friends are practically useless with relationship advice, good people, not good at relationships. I’m planning to go to therapy, maybe sort out my head. Am I overreacting?