Muscle weakness, bone pain, fatigue?

Female, 27, 5”2, 148 pounds..In May of this year, I randomly started to feel severely fatigue after taking my prescription Pantoprazole 40mg. Before I took the medication, something seemed off, like it looked different in thickness and color. Normally, the pantoprazole I get is small and dark yellow. But this one was thick , light yellow, & big like. However, it was still oval in shape and had the same letters & numbers the pantoprazole I normally get from my local pharmacy.

been taking pantoprazole for years & it always looked the same. So this was concerning to me. Still I took the medication and 2 days later I started to feel severely fatigue. This fatigue was deep within my bones to the point I couldn’t sit up. Like bone weakness. I continued to take it for 5 days, it progressively got worse so I stop it. It then progressively gotten worse and few days later I woke up and felt like my body was in sand is the only way I can describe it. My bones were also extremely weak. I called the Emergency room, they did blood work and said my phosphorus was low (which NEVER happened to me before) , & magnesium was a little low and that was all.

They gave me something to get my phosphorus back up & magnesium. I went to my regular doctor a week later as I was starting to now experience not only severe fatigue, weakness and both arms and legs, but now severe bone pain in both arms and legs as well as stiffness.

They ran blood tests, told me to get an brain MRI (which I then did and it was normal), the checked my ANA, all my inflammatory marks, bone break down, lupus antibodies, Akaline phosphate, calcium levels are high normal, they checked wbc, rbc, etc, Everything is normal. My vitamin d levels were a couple points low but are now currently normal since I started taking multi vitamin to bring it up.

I don’t know what happened with the medication I took, I was completely fine before it. This has rubies my life. Anyone know what could be wrong?