soon to be married advice

so me and my bf been together for 6 years ok so he wants to get married soon but I feel pressured.. the only reason why we getting married is cause we want to get baptized and the pastor said why get baptized if we still going to sin since we have intercourse and not married which he has a point there but I feel pressured I do want to get married then again I dont... I feel like my man mom hates me she yell at me and talk to me hateful. we use to have a great relationship we use go places together we use do everything together she was there when I gave birth to her granddaughter appointments while my man worked everything everything we use live together for few years me and my man moved she changed on me instantly... she loves My man's step brother wife and kids more now since they live with her. on top of that his wife is from the same country as she is so I feel like she loves her more because I'm white.... I feel like this is reason why I do not want to be married. plus my dad wouldn't approve either he don't like my man mom at all he know how she is to me... his mom is something else for real when I ask go her bathroom she yells tells me shut up... I do not like going to my man step brother bathroom is nasty and smells... so I yelled at for little things with her and she talk about my weight and she ain't perfect she is big to.... I just feel bad about everything.. other day she made me cry 😢 because I ask go bathroom and she yelled at me told me shut up...