Help Me Please

oki really need some advice. so me and my boyfriend went out during high school about two and a half years ago point is i broke up with him that time because he was leaving for basic and i didnt think i could do the whole army gf thing however i always loved him so we ended up getting back together about to be 9 months ago we actually talked longer than that but officially its been almost 9 months now. He deployed about 5 months ago to afghanistan and lately i feel really lonely and i feel like he's changed so much. He's not sweet to me like he used to the first few months he was really sweet and understanding now it seems like if i get upset he doesn't even care. he keeps saying things will get better but they just don't. I do everything for him! I send him packages tell him everything and don't even go out as much. I never flirt with guys i feel like i am puttting all the effort and hes over there. I try to understand but i can't. he has his family and friends support but i have no ones. My family doesn't support me and all my friends are with their civilian regular boyfriends. i feel like i need to break up with him i really cry all the time and he seems not to care, but the last time i tried breaking up with him i couldn't take it and we started talking again and got back together. he also threatens me that he's going to kill himself if i leave him and has been on suicide watch already. i really don't know what to do anymore is it me? oh and we both have strong attitudes and he's even had to take anger management. should i leave him or not leave him i would feel bad just leaving him through deployment but I'm so unhappy :( i feel like I'm wasting my time please help me!!