I (29) have known DP (28) for 3 years, been dating for 2.5. DP has what I'd call a very privileged life - she has no student loans, her house was a gift from her parents, great job, and she receives monthly supplementary income from her trust fund. I had a very difficult upbringing - single parent household, mum constantly stressing about money and work due having to bring up me and my sibling by herself.
DP is generally really nice, kind, and we love each other to bits. Sometimes however, I just feel like she doesn't understand things from my point of view due to how she was brought up and it gets extremely frustrating.
For instance, 4 months into our relationship she wanted to take a trip down to New Zealand. I couldn't afford it so she ended up paying for everything. Don't get me wrong I appreciated it so much but at times I did feel uneasy as I felt like I couldn't contribute anything and thus didn't have a say.
It's the same with our house. I basically live here rent free - she refuses to let me pay for anything as I've still got my loans and I make barely any money working in a non-profit - and sometimes it feels like I'm still a guest here. She also has form for complaining when I have to do overtime or work on weekends as she thinks I should spend time with her since they (referring to my workplace here) won't care. 
She thinks I am insecure. I probably am. I spent my whole teenage years thinking my problems were because I couldn't come to terms with my sexuality but maybe it's more than that. I feel like I'm slowly destroying the relationship with my personal issues and inferiority complex and I don't know what to do.