My Grandmother and I need a place to live

This month, I've been kicked out of my boyfriend's home. Why? Because his mother says my mental problems are ruining her son; I'm "not allowed" to be depressed and when I am, it means I don't love my boyfriend. We've been together for three years (high-school sweethearts) and were planning to move out in the fall. This change of events has left me broken-hearted, more sad than ever, and completely hopeless. My grandmother has offered to live with me to help cover the rent (right now I have a part time job, and it only lasts for the summer at which point I'll be getting financial aid for college), however the cost to move in is a tad over $1000. I just started my job and my grandmother is retired and unable to work. I'm saving every penny I have, but I'm asking for some extra help to get out of here before the negativity eats me alive, or before I have to live on the street. Thank you.