long distance sadness

Hi everyone, I'm going to try to keep this short. Right now my boyfriend of two years is in South America with a group of people livening there for three months. This is the longest we've ever need apart. I've been feeling very sad recently partly because he's gone and partly because I don't feel as connected with him anymore. I think this is mainly because every time we call he can never stay very long and I don't get to really talk to him and it makes me so so sad. Yesterday when I finally got in touch with him I completely broke down crying about this and kept him from going to a party that he wanted to go to and I feel really bad about that too. I'm also having alto of jealousy towards the People that he's there with, mainly the girls, and I don't know what to do about that either. If anyone has any tips or tricks or advice please share.