need help/advice (super long)

ok so my boyfriend of 4 years and I have been having a lot of issues lately. I'll be honest I've been kinda aggro towards life lately because I'm 'fustrated' if you know what I mean. I don't know what the cause is but our sexlife has dramatically declined I don't know if it has anything to do with it but about 9 months ago I had a miscarriage once again not sure it that has anything to do with it,but he still watches porn when he knows I have a problem with it especially because of the lack in intimacy between us. anyways I'm also aggro because he's never around and when he is he doesn't acknowledge me. it seems so obvious that he wants nothing to do with me he's even said it but he says its because I'm always upset... a good friend of mine is our neighbor recently he got a new girlfriend in which mine and his friendship has kinda faded which I totally understand but ever since she moved in my boyfriend is ALWAYS at their place and I'm never invited and any time I just go with you can tell that everyone feels uncomfortable,but the thing that bothers me is she is always wearing really exposing clothes (sports bra type shirts skirts see through leggings ECT) and the thing is my boyfriend literally hates my friend he always has and EVERYONE knows this but yet he keeps spending so much time over there. it got to the point where I asked him if he could please not be over there without me because I'm going crazy about the situation and can't stop my head from wondering. he said ok but it's like the conversation never happened cause he continued and I talked to him again about it. I even found out that a couple of yimes of times of times her boyfriend wasn't even there. by this point I asked him to please not associate with her anymore,yes I know I can't control him,but you'd think if he 'loved me with all his heart' like he claims HED want to do it himself. but same result. well on night he was being really f***** up to me so I left to a friend of ours (btw he's gay) to vent. In the way early AM I came back the sun wasn't even out yet and he wasn't home.so I went outside and my neighbor was outside I asked him if he'd known where my bf went thinking maybe he might've told them he then told me that him and his gf and my boyfriend went to ride the bike path in a natural reserve located like half a block away, and that his light cut off so he stopped to fix it and told them to hold up apparently they didn't . We went looking for them and couldn't find them so he thought that maybe they returned home which is why he was outside. Which at this point my heart was racing and my mind was running wild. I sat around waiting and waiting 5 hours passed by this point the sun has been up for about an hour maybe hour and a half when he and she came riding up. I felt really betrayed and hurt and I just said 'are you f****** kidding me right now really' he just responded with 'dude stop the bullshit im not playing your f****** games ' I had nothing else to say to him at that moment but I told her ' look if this s*** happens again there's going to be f******* problems to handle ' she said nothing and went to her place . At this point I'm crying cause I feel betrayed and disrespected even worse I felt totally neglected. Since then my boyfriend has been flipping out on me about everything staying gone from home way more and still goes to their place.which all makes me feel 50x worse so I'm always really hurt,in which he's tired of and doesn't care about when I feel that way. I just don't know what to do I love him to death but I'm really hurt by my situation.. he says if I weren't how I am then he wouldn't be how he is doing what he's doing I keep telling him that I can't help the way I feel because of the things he does and if he'd just treat me anything like a girlfriend even a tiny fraction of what he used to then I wouldn't be like this or seems like a never ending cycle n he says he's no going to stop or change what he does in life. I'm just so hurt and pretty much venting .sorry ...also he keeps telling me to get over it .