Why is my Birth control causing depression a year after use?

I have been on the same birth control for over a year. In the past month or two, I have become extremely sensitive, I feel lonely and I don't like myself. I cry daily, often at simply the thought of how sad I am or about my boyfriend and I breaking up. I take offense to a lot of things, am very jealous, get easily annoyed by people and I find that things consume my thoughts for hours that I don't want to think about at all. I am taking an educated guess and saying that the cause is my birth control. There is no other pill that I have recently begun to take. It is starting to effect my relationship because of my super-sensitivity. My boyfriend has begun to think that I am just feeling sorry for myself but I really cannot help the crying. I don't want to go off the pill and I'm not sure that my insurance covers any other kind (I am on the generic version of Allesse). My emotions are beginning to affect me in social situations and it's very embarrassing. I'm so unhappy. Could someone please provide me some insight into why this is only happening after more than a year of use and something that I could do about it? Thank you.