The mouth ulcers could be indicative for viral or fungal infections.
Swollen gland and tight muscles around your neck and shoulders and back are indicative for infection of the :
whether bacterial, viral or fungal infection.
A good examination by an ENT specialist
is needed together with culture of mouth/throat swab to determine the right origin of your problems.
I'd advise to :
- keep good oral hygiene
- avoid citrus food, too hot or too cold
- avoid carbonated drinks
You can send a photo of your mouth ulcers to me to assist you further!
Wish fast recovery!