1. since having horrible taste, swollen gland mentioned by you might be [sialoadenitis which is an inflammation of the salivary glands (a bacterial infection)], [ since saliva is essential for the normal functioning and health of the mouth resulting in bad taste and burping], see an ENT or dental doctor.
2. swollen [lymph] glands are usually a sign of infection or disease in the body, and requires examination by your Doctor to feel for the consistency [firm, mobile,rubbery,fixed, or non-mobile]
3. since blood test
report is yet to come, one can go for a biopsy
[where a small tissue sample from the lump is taken and send fro investigation], likewise an X-ray or CT scan
is recommended after consulting with your Doctor [since site of swollen gland is not mentioned thus which part to screen cannot be told]
4. if Doctor finds out that this is a local infections, you will just need to drink plenty of fluids, rest and relieve the symptoms at home using over-the-counter medicines such as paracetamol
,if it is generalized swelling then one has to look for some Autoimmune disorder,whereas if bacterial infection comes out then antibiotics are the main stay of treatment.
. getting tired easy [weight loss] could be one symptom of underlying inflammatory disorder, check with your Doctor if you're concerned.