What is wrong with my cat?

My cat angel is 10 years old and lately hasn't been herself and i want to know what is wrong with her she is losing hair on her backside and scabs as well,she has blood in her stool, she has been hiding more often behind the couch, and when you try to pick her up she makes a weird meowing noise. Plz help me out i want to help my cat and treat her if anything is wrong.