Welcome to HCM
We understand your concerns
I went through your problem description. I am really sorry to hear about the accident. Get well soon.
Regarding your chest tightness
and mild pain. As the doctor did all the tests and they could not find any problem, the tightness could be due to two causes. One the acidity induced due to the intake of antibiotics. There must be medicines to clear this acidity. Second is the anxiety
associated with the accident episode and the lameness with it.
This could be Post Traumatic Stress
Disorder. Don't panic. This should be cured naturally after some time. This PTSD
happens with everyone after an accident. Be active mentally and physically as much as possible. Also read lot of interesting books while on bed.
Hope this answers your query. Available for further clarifications.