Thanks for posting your query.
Dry mouth can lead into high incidence of dental caries
which can lead into abscess under the gums resulting in swollen gums.
White and red spot like lesion on gums may be due to-aphthous ulcers
I would advice you to get a thorough clinical as well as radiological examination of the inflamed area done.
If required -root canal treatment
,drainage and curettage of abscess has to be done.
Get your teeth cleaned.
mouthrinse to gargle.
Vitamin becosules,iron and folic acid supplements has to be administered.
Take fluids and nutritional rich diet.
Avoid anxiety and stressful jobs.