Feeling Unappreciated and In Pain at Work

I don't know what to do. I'm back at work after the holidays and I'm already stressed, feeling like I'm not good enough for this job because people talk around me and never to me, if it is to me it's never nice comments or it's demanding when I can't do it whenever they want. I've been here nearly 3 years and it's getting worse. My Scoliosis and Occipital Neuralgia isn't being taken serious, there's been no adaptations to my work and I'm always in constant pain. I have been trying to get a risk assessment for months but they don't care. I feel like I'm being talked down to like I have no knowledge, around so I have no feeling of inclusion, feeling like I just want to jump off a roof at this school...I'm in a really self destructive mood...