Feeling depressed everyday, telling myself to breath.?

I'm 20 years old and recently started feeling really sad for no reason at all. I feel like no one understands me. I'm in a relationship of 6 years with my bf and i love him dearly! I feel it off and on all day everyday. It started a few months ago. I also have breathing problems where it feels like I have to tell my self to breath at a pace. It freaks me out because I think I'm going to pass out. Seems like all I want to do is sleep so my mind will do the breathing on its own with out me having to think about it. Sometimes i cry and I dont know why I'm crying. I started reading the bible too. It comforts me a bit. I still feel really depressed though like why am I living? Whats the purpose of life. It's driving me crazy. I do think about suicide but i never will considered it....yet. I Just don't know what to do. :( I live in Manitoba Canada. Should I see someone, is there someone who feels these things? I really need someone to talk to. It's effecting my life....