I am on the deed to my home with my girlfriend but not on the actual loan can i claim it if we both pay 50/50 on the mortgage?

Yes, it sounds like you qualify. To take the deduction, the rules say you must:

1. Have an ownership interest in the home OR be liable for the mortgage payment

1. Not deduct the same amounts twice (meaning you and co-owner don't deduct more than total interest)

See the answer below for more info:

https://ttlc.intuit.com/replies/3875555