I’m scared to get married..🤦🏼‍♀️

I am 19 years old, I’ve been with my fiancé for almost 2 1/2 years we have a 16 month old son. We planned to get married April 16th 2020 just to get it over with. It seems like we almost break up every 6 months. Ever since I met him I’ve been scared to commit to him fully. I think I’m so stuck on wanting to be married, a family, and living on my own that I’m not thinking of my relationship with him. I’ve been questioning myself since October. My sister said marriage doesn’t change anything that we will still be the same person. I’ve been questioning myself before my son was born... I really don’t know what to do