I don't know

So I been with my boyfriend for 9 months now and i love him so much . but everytime we are together I'm really really happy and I love the time we spend together and I love the feeling I have when I'm with him I love him being with me all the time but the thing is that everytime he leaves me like when he goes home or leaves me for at least 3 mintues or so I get depressed ? and all mad ? and I'm mad and depressed all the time that he is gone but when I see him again I go back to being all happy and all . this barely have been happening since January 8th