Any advice?

I've been in a relationship with my boyfriend for nearly 6 months. He broke down a couple of weeks ago, saying that he was scared of losing me and that he felt lonely - at the time he was falling out with a few of his friends. Since then he has got back in touch with those friends and his attitude towards me has changed a lot. He hardly talks to me now, it seems like it takes him so much effort to have a conversation with me. It upsets me a little when I see him post things on social media with his friends. I've always been quite a jealous person and I get attached very easily. I fear that this is possibly pushing him away from me. I am starting to doubt his feelings for me, I think he only wants me around to say that he has a girlfriend.