Neurology :: Muscle Fatigue And Perceived Weakness And Twitching

I have been having a slew of health problems recently but am still awaiting further testing. In the meantime, I am very stressed and having a hard time managing. I keep getting worried that my symptoms could be onset of ALS despite knowing how illogical it sounds. I am a 25 year old male.

First, I was diagnosed by my doctor with a sinus infection, although it was probably very slight. She prescribed me Augmentin and I took it for 5 days and immediately started feeling bad on it. After I quit taking it, I noticed some tingling in my hands and feet at work on Thursday the 11th. The next evening, Friday, my legs started to feel unsteady and heavy when I walked and my hands and arms remained tingly and had perceived weakness. On Monday morning, the 15th, I went to the ER and they believed I had Lyme Disease and prescribed me doxycycline. I took this for 7 days, but did not feel any better. I remained having perceived weakness primarily in my legs accompanied by muscle tightness, muscle soreness, and very slight, sporadic twitching all over. On the 19th, I saw a neurologist who dismissed my symptoms as not serious as my reflexes were ok (knees were slightly weak, but I was very tense during the test) and I was able to walk normal, it just felt strenuous. My lyme test came back negative and a second western blot also came back negative.

Currently, I continue to have all of my symptoms, including perceived weakness, muscle fatigue, soreness, tightness, and twitching.  Symptoms are present all over my body, but concentrated in my legs. When I lay down at night, my whole body will feel as if I had a sunburn and I am having difficulty sleeping because of my worrying. If I go out and walk, my legs gets very sore and tired much quicker than they ever did before. Additionally, I have been having a very dry mouth and tight feeling throat. My PCP believes it to be either post-viral syndrome, mild MBS, or the least likely, MS. Others have suggested b12 or vitamin d deficiency. I have an MRI scheduled next week and an appointment with a different neurologist.

Other info:

-Was prescribed zoloft and am less than one week in to taking it. I believe it may be increasing the shakiness of my hands and my stress, as it takes some time to adjust to it.

-Was prescribed ambien to sleep. I'll sleep for about four hours straight, but then have a hard time continuing to sleep once I wake up. I believe I might be twitching or jerking in my sleep which wakes me.

-I tried to go to the gym on the 24th and run and lift weights. The next day, it felt like it really set me back, as I was much more sore and my legs seemed more unsteady.

-Began taking b12, b complex, magnesium, D vitamins.

-Had multiple blood tests. The only abnormal result was a positive ANA for speckled at 1:80. I read this can be a pretty common result.

-Less than 2 years ago, I had shingles.

Any thoughts on what could be wrong with me?