Ohio Workers Comp PLEASE HELP?

I was injured at work by twisting my knee. It has been 10 days of hell. I have only been off work resting for a total of 4 days ( this goes off a 5 days work week with 2 days off) and other days have been "light duty" which actually made my injury worse. I am 21 years old and the knee is feeling a little better. The first Doctor did an Xray and found fluid in the knee but would not do an MRI i have seen another doctor through the same urgicare and a orthopedist referred to by the urigcare my company sent me to. Both the second doctor and orthopedist have refused to do an MRI on my knee. I am doing my best to go along with the rules but i am becoming concerned that they are trying to send me back to work and i have only had ONE xray a week and half ago that showed fluid in the knee and NO MRI. My chiropractor want me to get an attorney and send me for an MRI. So if you're still reading THANK YOU, so my question is should i go with an attorney to protect me and get an MRI through my chiropractor? I am in no way looking to make a court case and sue ANYONE i just want to be assured nothing is torn and there is no cartilage damage. I am not good at being an asshole which usually means i don't always stand up for myself. Also in the state of OH can i be fired from my company over a workers comp claim? (i do have a union) but legally can i be fired and if my chiropractor makes me sign up with an attorney just to protect me will my Company go on the defensive and turn this into a court case? ALSO lastly my company is self insured for workers comp. THANK YOU SOOOOO MUCH FOR ANY HELP please ask for any further detail and i will provided.