I understand your concerns.
Your neck swelling could be due to thyroid
swelling or lymph
n ode swelling.
Consult a general physician to confirm.
Tightness around neck may be due to anxiety
Thinking is a process and cannot be stopped even in sleeping.
We have to strreamline our thinking by actively engaging in work, leisure time activities, hobbies etc.
Worries cannot cure dieases, worries encourage body problems to go on.
But being happy even though you have problems, can cure your problms.
Wish you a good future.