Dealing with my boyfriends sister and mother

Hello, First of all, thank you to anyone who responds. My boyfriend's sister and I were good friends before he and I started dating. We weren't friends for that long, though, only a couple months and we became friends because we worked together. She mentioned him to me one day and he and I started talking online for a few weeks before we met. One night we both went out for my friend's birthday, met in person, hit it off, and have been together ever since. His mother and sister are really close, so everything I told his sister about our relationship or things we did, etc. were repeated to his mother. From the beginning, they were all involved in our relationship daily, as I told her things as a friend (which I am regretting now) that she repeated to their mother. Not too long after we were dating, his mother was contacting me on a daily basis, through email or text, talking about her day or my boyfriend and I, or his sister's problems (she has some personal things going on), even texting me when my boyfriend and I were together. She would tell me family things before he even would like he and I had been married for years. I wanted her to like me, so I kept in contact, even to the point that I look back on it as unhealthy and not normal. His sister and I worked together for a few more months after we started dating, but then she moved on to a different job not by choice. From the second we stopped working together, she would be depressed if she did not keep in contact with me daily or hang out with him and I on the weekends (I heard this from his mother, and she would also tell me and my boyfriend this). She had no problem being the third wheel. Whenever she would come to my house, her family had to come pick her up, so I would also be seeing his mother on a regular basis. They both would consistently talk about he and I getting married to me and others, and one time I had a stomach issue, and they were both convinced I was PREGNANT and told me how happy they would be if I had a baby (not okay). His mother even went to the extent of introducing me as her future daughter-in-law to her friends. They both also have access to my Facebook and social media, so everything I post they include themselves in. As I said, I went a long with this for a while, but, the more I would think about it, the more I would realize this was not normal. His sister was living as though she was a part of our relationship. She wanted to be a part of his group of friends as well as mine and could not find her own life. Once again, with the social media, she is constantly all over my friend's and his friend's things to the point where I cannot click anywhere without seeing her name. I finally caved and deactivated my social media so I would not have to see either one of their names. A few months ago, I talked to him about it, and told him my feelings. He talked to them a little bit and they both got upset and mad, which is understandable but I do not feel bad. They have backed off a little bit, but, it still seems like I give them an inch and they take a mile, even to the point where I told his sister him and I were going away with another couple a few weekends ago and she called my boyfriend and told him I invited her to come. Who would even want to go with another couple anyway?!?! Even though, they have backed off somewhat, I still can't help but to think things will not get better. I am scarred and do not know how to get past this. It may be a 'me' thing now. I realize situations could be a lot worse, I just do not know how to feel better about this situation and am worried I will never be able to relax about it again.