Please for the sake of your health and well being file a work comp claim. If there is an if and or but about your health and you know work caused you to be disabled or sustain injury go to the damn dr and get a work comp claim filed. If work retaliates against you; file a union grievance as this is not allowed. Unless you opted out of insurance you have it. Your job is on the line if you call out consecutively because of an injury. 

Remember if you call out repeatedly work can and will enact attendance policy and even suspend you for it. 3 or less call outs a month scattered through the month is fine. 3 or more days in a row you require a dr note. 

Get a damn dr note and get your self diagnosed so you can heal. I grew up christian science and my family refused to take us into the dr for simple procedures and diagnoses. So it left us with life long scars from the "natural" way of healing. Please go to a damn dr. If you value your job you will and are allowed fmla and a work  comp  claim.