Muscle pain/twitching/cramping as main symptom? Does this sound like Lyme?

Hi everyone, I am fairly new to the Lyme world and have some questions..

So I spent a lot of time this summer outdoors in Missouri and Montana. However I have lived in Missouri for a long time and have been bitten by multiple ticks. I never noticed a bulls-eye rash. When I returned to school this fall I started having extreme fatigue and days where I would wake up feeling fine and half way through the day I would hit a wall, like I would feel like I was coming down with a severe flu, nauseous, shaky and feverish. During this time I also had severe headaches, IBS symptoms, random itchiness all over my body, much sweatier than usual, and a pimple like rash that popped up all over my thighs. I knew at the time that I wasn't feeling well, but my symptoms were so weird and random that I tried to just shake them off and continue on with my life.

These symptoms subsided a bit, but then I started to get muscle wide body twitching, cramps in my legs while working out, and overall muscle fatigue. The last time I tried working out I had to stop and I haven't really worked out since. For about 4 days I had EXTREME pain in my neck/back/shoulders. I felt like someone had taken a hammer to my back and the pain was just radiating. This pain landed me in the ER twice where all blood work, chest x-rays, etc. were normal. The doctors seemed to think I was crazy and sent me on my way without any sort of diagnosis.

During the time of the severe pain I started to have severe anxiety symptoms. I was having 2 panic attacks everyday, was nauseous all of the time and was not eating or drinking much. I managed to get these under control with a little bit of anxiety medicine with a new GP I was seeing. I told him about all of my symptoms and he too thought I was crazy and prescribed me the anxiety medication. After doing a lot of my own research online, I found Lyme Disease and it seemed like it fit my symptoms pretty well. I asked my doctor to test me for it. He did an ELISA test and the results came back negative. I managed to convince him to prescribe me doxycycline 2xday 100mg, that I have been on for about 2 weeks now. A couple of friends put me in touch with a couple of people who has Lyme and they suggested I visit Lyme disease specialist which I did. She told me that my symptoms sound like they could very well be Lyme, so I did A LOT of blood work and more urine tests that she said should be able to pick up Lyme and other co-infections. She suggested I stay on the Doxycycline until those results come back.

So, what I want to mainly ask is about my symptoms since I have been on the Doxy. I feel a little better, less nauseous with more of an appetite. However my neck, shoulders, back, basically all of the muscles in my body are EXTREMELY tight and in knots. Many of them are painful to the touch, and my right thigh is often cramping. I feel like I just ran a race after walking up a flight of stairs and get out of breath very quickly. I am also still having body wide twitching, spasming, and overall muscle pain. I have even noticed some muscle weakness on the right side of my body I think. But overall the symptoms have been worse on the right side of my body. Epsom salt baths give me relief for the rest of the night when I take them, but when I wake up in the morning I am once again extremely tight and in pain.

I am wondering if this still sounds like Lyme or if I should be concerned it is something worse? Has anyone else had an experience like this?