What have i done to deserve him doing this ?

im struggling to try and understand what ive done so wrong. ive been friends with a guy 3 years, during this time ive helped him endlessly with work, money you name it, been a shoulder for him and i do like him a lot. he did give me the impression he liked me too but we remained friends. lately he makes me feel like a nuisance and wont take my calls etc which has made me panic and as a result text more which im ashamed of. if he needs money hes there and is sweet but changes very quick. he also lies a lot to me and i dont understand what ive dont to deserve this. i still have to work with him so cant just cut ties but he gets a thrill from me chasing him and im sick of it. what shall i do pls help me