out of control

I just got married in February. we were very happy. we got along fucking amazingly!! he was the perfect husband and i thought i was decent enough wife. we moved into a bigger apartment and got a roommate to help pay for it. im guessing the roommate already had a drug problem and my husband used to do party drugs but hadnt in the 3 years we were together. now my husband has been doing meth for the last few months. i only found out about it the last few weeks. but it explains his behavior. im now 4 months pregnant. he's gotten mean. he can be ruthless.its usually just verbal but he has pushed me, grabbed my arm, he did it last night and scared me so bad i was going to leave at 2 am so he wouldnt hit me. he didnt even try. ii just slept on the couch til about 5 or 6 then went to bed. i have said something but it doesnt seem like he wants to stop or is even willing to do it for his baby. he is not the person i married at all.