Feeling down and lost

I just do not know what to do anymore. I love my life yet at the same time I don't. I have an amazing boyfriend who loves and takes care of me and I truly appreciate everything he does for me. Yet sometimes I feel so annoyed by him. There are times when I just don't know if I want to continue the path I'm on. We have talked about getting married and we already bought my engagement ring. And I am excited about our future I really am, but yet I don't know if I am (I know it doesn't make sense). I feel so down lately however I am on the depo shot and I'm wondering if that has something to do with my mood. I'm also just worried because the place my boyfriend and I work at might be closing within the next year and we are trying to buy a house so I am just worried about it all. I don't know. I'm sorry if this doesn't make any sense at all. I just needed somewhere to vent and get my thoughts out.