manasiti

I have a very low gpa of 2.3. My GRE is 322(161 v, 161 q). Though I do have a reason, my younger sister had cancer while I was in first and second year, she passed away when I was in my third and it was a lot to take in. I am in my fourth year right now and am doing much better than before, trying my level best. Also I really want to change my field, take psycology for instance. I just dont know how to contact professors and talk around and what to say. Moreover , I dont know if I have any chance. Please advice!