Relationship Advice Please :(?

My boyfriend hasbeen a bit distant from me recently. I met with him last night and he was in a really funny mood. We'd made plans to go to the cinema together but when I arrived he kept saying 'I can't be arsed with this s*** ' He then played on his playstation 3 all night and played his guitar with no affection towards me what so ever. Only when he saw me upset the mood lightened and we were okay again. I asked him if i'd done something wrong but he said no. I apologised as i think maybe i've been too forward lately. The other week I told him I loved him and i'm always expressing how much he means to me and how much I care about him. But recently he's not been saying it back. We're still sexually active and it's only been a couple times that this has happened. But I don't understand why? Also, he has a best friend called Emma. He spends time with her but I know for a fact nothing will ever happen between them as they've been friends for 9 years. But I still feel threatened as he's always updating facebook about how much of a good time he's had and always seems so much happier when he's with her and even his other friends. I've not told him about this because i'm scared he'll think i'm jealous and clingy. It's only because i feel like he thinks it's a chore to be with me. The first time that he was in a funny mood with me, it was stopped by having sex. By this I mean, as soon as HE initiated the sex and we did, everything was back to normal and he was acting normal with me. And we had a perfect day. I'm really confused, please explain this to me?

Some extra details: I've been in a relationship with my boyfriend for just over 4 months and i've never been happier. We've been very close for 2 years. I waited for him for 9 months while he travelled the world and I can safely say i'm in love with him. He's 4 years older than me. We first dated in March for a month but we broke up as he cheated on me. However we got back together at the end of May. And we both feel that it was a really good decision to get back together and we feel that it's so much better than the first time. I really really love him and all I want him to know is how much I care about him and love him. I'm terrified of losing him as he's practically my world and I can't IMAGINE living without him and it just reminds me of how much it hurt when he broke up with me last time. Another thing is, because it's been upsetting me, i'm now forcing myself to be a little distant so I don't seem pushy (so not texting him first and not constantly telling him how much I care about him. But possibly you could explain why he's acting like this so I can think about what the right this is to do? If it helps: we're both Aquarius. Thankyou!

Suggestion:

i would suggest that you start spending a bit of time with your other friends arrange to see him 2 3 times a week for few weeks so you can build your confidence back up also invite this girl along to join you do something to show she isnt a threat n that your cool with it. maybe text him one day but leave out the love you n kisses etc then dont for a couple days n only put them if he does show him not only does he have a fab girlfriend who lets him have girl mates but she has a life of her own to make a few new friends including a few lads start doing things as a group once a week or something so it takes the presure off you n him. do not however start using sex as a way to get him talkin again as if he thinks all he has to do is be a jerk n his gettin laid after he will see it as a good thing so if his an idiot tell him he aint gettin any unless he makes it up to you. say you are scared your gonna loose him again which is worrying you n that you waited so long to be with him loosing him hurt so much you dont want that again so if he isnt serious about you then he needs to set things straight now but if he is like you think n hope he is he needs to start actin like it. set time aside for each other alone n time apart as being together to much not only means annoying each other living in one anothers pockets but if it ever went wrong even for a week after a fight you have no one to fall back on. maybe spend some time with this girl on your own n get to know her say you want to widen hyour social circle that he can still have time on own with her but you want to get to know her as she is a big part in his life n think it would be good to know why.