Worker's Comp. denied me mental health treatment after injury

I was injured on the job and the doctor they sent me to would not allow me to go back. He said that I was Permanent & Stationary. He also referred me to see a mental health therapist because he saw that I was getting depressed. Worker's Comp. sent me to their therapist to see if my problems were related to the injury. I got a letter in the mail that stated that my doctor's request was denied because they didn't find enough evidence that my mental health issues was because of my injury. The letter said that they wanted the okay to get my medical records from my primary doctor. I refused and they didn't let me see a therapist. When my doctor found, out he prescribed me an anti-depressant but worker's comp would not pay for the meds.

Between that time and now, I have been diagnosed with sever depression and my therapist believes that it had to do with my injury and the fact that I could not go back to a job that I loved and was going to school for. I have had a few suicide attempts and have been psychologically hospitalized a couple of times.

My question is: Can I sue worker's comp. for not treating my mental health needs even though they said they will pay for all my medical needs? It is in my mental health files that the work related injury and the consequences of the injury caused the depression. My worker's comp. doctor saw it coming and asked for help from the ins. and they refused. Is it okay for them to do that?

I haven't heard from Worker's Comp. for about a year now and I don't know where my case is now. I did not sign any papers.

If you can help please do

Thank you.