I paid rent in my girlfriends house. She threw me out, threw some of my stuff out, and has packed my things. I got no notice and it came out of the blue. I live in rochester, ny. I've been staying in hotels since. What can I do?

If you have been paying rent, you would be a tenant. How did she "throw you out"? Telling you not to come back is one thing. Locking you out would be another, for which she might be required to pay damages.

If she locked you out and threw your things away or destroyed your belongings you sue her.
If she told you to get out and you just left ( you did not have to) and nothing of yours was lost, there is nothing you can do.