What you are thinking about doing is a very big step and you really need to think things through. I know you want out of your mother's home but what is going to happen if you and your boyfriend break up? How much financial support are his parents willing to give you and for how long? Are any family members willing and able to take you in instead of your boyfriend's family. There are so many things to consider so I hope you will be very careful and I wish you well!