Frustrating situation

Alright so this is going to be a sort of rant/invitation for suggestions type post.. I'm sorry if It's very long, hence.. It's a rant. 

First off I'll start with the fact that I have social anxiety/anxiety, depression, and PTSD so standing up for myself or standing up in general against people is very difficult for me and not something I do often unless a nerve has really been struck. My fiance is the same way in he chooses his battles and most of the time is very calm and patient and not one to stand up for himself either.


My fiances name is Spencer. He is incredibly sweet, caring, protective, calm and patient. He is an extremely hard worker and just an absolute gentlemen. He's never rude, or snarky, always willing to help out or offer help to his parents/ to me and my fam. He thinks of others before himself all the time and never complains about anything. 

A little over a year ago we started dating ( he's great, everything I've wanted) and now we are engaged to be married. As long as I've known him his parents have been quite...unfair? To him. He is adopted and has 4 other ''siblings'' all older than him. From what I've heard his parents have always been very controlling, and rude towards him and i believe it because i've seen it. He has gotten in trouble for very small things... He was walking down the hall one day to the room ( normal walking) and his mother screamed at him and said he needed to '' not walk so noisy, there are people downstairs'' ( there was no one else home and it was the middle of the day). 

He is constantly sh*t on for very very small things, or things that aren't his fault/ not even something worth getting mad over. He always offers help around the farm before anyone else but is constantly told he is '' lazy'' and '' doesn't help out''. Which is bullshit. his parents will ask him how his day is and he will answer and they will attack him with rude comments. Recently we moved out from his room and into the new basement suite in his parents place. ( We are both 19, he will be turning 20 next month).. So yes we are still young and still figuring things out and it's all very new to us. Spencer has a good head on his shoulders, is very mature for his age and has a lot of common sense. He has got ahead in his life a lot faster than any of his siblings ever did. He is hardworking, making money, taking care of his responsibilities, but his parents continue to shit on him. They are still controlling towards him and treat him like a child when he is paying rent and planning for our wedding. When he told them he recently got a promotion at work they had nothing but horrible shit to say to him and got mad at him... When they should be proud, I know I was. Anything he says or does, he gets attacked. His mom tries to shit talk him with me behind his back, which does not work. 

His dad is an alcoholic and very rude. A while ago while him and I were sitting in our suite that we are paying rent for, his dad came to the window screaming and swearing at us about it being open, and slammed it. ( he was drunk) and of course his mom came to his dads defense saying he didn't do anything , and he didn't swear. I grew up with my parents constantly fighting and treating each other like shit.. So being screamed at is a bit of a trigger for me and it makes me very nervous and uncomfortable. 

So far living here I've watched spencer constantly being controlled ..and we've tried to stand up and it's like talking to a wall. His mom is now trying to control our wedding, which since we aren't letting her, she has her nose in the air, and is treating us like dirt, telling us we're embarrassed to get married and it's not our wedding it's her families wedding.. All because we aren't getting married where she wants us to be married. Which quite frankly is a very stuck up golf course that costs 10 k. I don't feel like paying 10 k to have some huge wedding and make my anxiety crazy bad just so she can impress her side of the family. Spencer and I are both quiet, shy, keep to ourselves type of people and we do not feel like a huge, stressful wedding. Yesterday we went to look at a venue, and it was perfect, exactly what we wanted.. My family loved it, i loved it and so did spencer.. His parents who insisted they come stood off to the side the entire time complaining and making rude comments about the place. My family decided since both spencer and I aren't really into being in front of a lot of people that they'd make a list of people to come to the wedding, and his mom could make one, then they each give us the lists and we pick and choose who we want, so that it's fair for us and we don't have people coming we don't like/know.. We both liked the idea and brought it up to his mom. She wasn't having any of it. She got mad and said '' YOU CAN'T CROSS PEOPLE OFF MY LIST! THIS ISN'T YOUR WEDDING, ITS OUR FAMILIES WEDDING!'' Which guess what.. Now she doesn't get to make a list at all, she has no say and spencer and I are making our own lists.

His parents like to hold things over his head.. Like money for the wedding ( which doesn't matter because my family said if that's the case they will help completely) and his rides to work. He currently does not have a license which he is working on getting, so in the mean time they like to use that against him if he doesn't do everything they say.So far everyone I've talked to says we need to get out of this house and move, but we just don't have the money right now and won't for a year or so.. Even his brother and his fiance said they could not stand living here and that it's absolutely absurd some of the comments they have made towards us. 

I was wondering if anyone had an suggestions to make these next few years a bit more bearable? Or any possible way to get his parents to stop being the way they are towards him....?