Will I be accepted in the hip-hop community if I'm white and come from a middle class upbringing?

It really depends. White people tend to support other white people. That’s how artists like Eminem, G Easy, and Macklemore blew up. I would say if you deal with emotional issues, that’s a topic that breaks down barriers. Black people and white people both listen to to JuiceWrld, Mac Miller, Lil Skies, Drake, etc. 

Your story sounds very similar to that of someone else who became a big deal in the hip-hop industry: Eminem. He was someone who was very passionate about what he was writing about. Unlike most artists today, he didn't play it cool and talk about women and money and all that crap. He talked about the sh** he puts up with and even though I don't like hip hop that much, if I had to choose my favorite rapper, it'd definitely be Eminem. Take a look at his stuff from the 2000s and early 2010s. His more recent stuff sadly sounds just like all other trap music today.

If you act like a poor, oppressed black,
you Just Might get away with it.