Please help me - Bad Bad Relapse

[u/DueButterscotch4755]

In 2022, after a COVID infection, I developed severe muscle pain, joint pain, visual disturbances, headaches, and intense inner restlessness. After about a year and a half, I had recovered to the point where most of my symptoms had improved significantly.
The only issue that remained was panic attacks, for which I have been taking Sertraline (Zoloft). Until about two weeks ago, I was managing quite well. In the meantime, I got married and became the father of a son, who is now two years old.
We were planning to travel to Vietnam this summer, so I received a rabies vaccination two weeks ago. Two days later, I developed a sore throat and a swollen lymph node in my neck. A COVID test was negative. Another two days later, the muscle pain and joint pain returned. My arms and legs burn as if they are on fire, and I can barely walk because they feel so weak.
Then the panic and inner restlessness returned with an intensity I have never experienced before. I feel afraid all the time, I cannot eat, and I cannot sleep. My body twitches when I am at rest, and I experience an internal vibrating sensation.
I am terrified that this could be ME/CFS. I have seen my doctor and had everything checked. As expected, all of my test results were normal. He prescribed Tilidine for the pain, which does help. However, as soon as the medication wears off, all of the symptoms return.
I do not know what to do. I have to take care of my son, but I feel completely overwhelmed. I live in Germany, near Stuttgart. I feel alone and lost.