How do I deal with my over protective boyfriend?

I’ve been with my boyfriend for almost a year and 3 months. Things have got a bit too much lately. I lost my best friend a few weeks into the relationship, and she got pregnant and really needed me, except my boyfriend told me she was horrible and he hated me talking to her, so I stopped to save our relationship. The arguments came up a few times but I’ve only just looked into dealing with it. A few months ago, he got funny about me spending time on things like msn and a social site. He’d stalk me on a social site everyday and read all my messages on msn. Eventually, he told me he didnt like me going on it. So I cut back a bit, and spent more time with him. I’ve only got about 3 or 4 friends left now, and they’re hanging by threads. I never spend time with them or see them. About a month ago I deleted my a social site. I told my family and friends I deleted it because I never went on there. But secretly its because he hated it. I was talking to a friend on msn the other day, and when he asked me what I was doing, he had a major mood drop and told me I’d upset him by going on msn. Instinctively I turned it off. I didnt want to upset him. Im really scared of losing him, but its getting a bit too much…