HI, thanks for using healthcare magic
The knot is likely related to the shoulder exercises that you were doing.It may indicate that one of the muscles is tense or in spasm.
Sinus disease would not causes any changes such as you are describing. It would normally be associated with post nasal drip
, nasal congestion
, sneezing, coughing, facial pain
Sinus disease would cause the drainage that you experiencing.
You can use a topical nasal spray
and antihistamine to help with the post nasal drip.
If your shoulder is painful then you can use an anti inflammatory pain killer such as ibuprofen, cataflam.
I hope this helps