Coming Out Support Group
This community is dedicated to the challenges that gay men and lesbian women face, both between the partners in a relationship and from other influences (family, society, etc.). Find support and talk to others who may be facing the same challenges, and share your experience.
Each generation has been 'trained' to think and feel the way they do about our sexuality and theirs. Though it may be hard to understand, your mother may hold her beliefs 'honestly' or at least from that training. If that is the case, acknowledging her unease or distaste, while holding your ground about your own beliefs and convictions, may go a long way to letting her find a way to drop her bullying stance.
If this does not work, you will have to take a deep breath and prepare either to sever the relationship for a while, or bulk up for the long haul. Though I sense and feel you pain, I also admire you immensely for doing the thing I lack the courage to do...coming out. Stay proud of who you are and if possible keep your love for your mother alive until she can find her way back to you. If nothing else...know that a perfect stranger has mad respect for you.
....and....please seek either professional help for the depression or at the very least a good support group. Joining here was a brilliant move! See, you are smarter and stronger than you think!!