What to do with this negativity?

I just told my mother i failed the regents for algebra 2 and physics...shes now avoiding talking to me and is acting like it affects her life so negatively. She uses this negativity to make everyone in our home feel like garbage and i cant stand it anymore. Im upset at myself tremendously but she as a mother has never encouraged me through school only nagged about how im lazy when i do try. I cant stand living like this anymore because its like this everyday and she blows every little thing out of proportion...its driving me crazy and so rar my teenage years have sucked beyond belief