I feel large lumps on both sides of my neck, under my jaw. i'd say they are about an inch or so wide. could those be my submandibular salivary glands? they don't really move. they are not hard, but not squishy either. they don't feel like lymphnodes?

It could be Swollen and infected Submandibular glands , a course of Antibiotics is the first thing I would do, have a Dentist see you , if nit resolved need to have Biopsy since still Cancer or Lymphoma is a possibility until ruled out .

The area contains many tissues. Submandibular glands share a good potion of this space, and you may have more pronounced volume of these glands. The "lumps" may be from more fat tissue in the area--this does not necessarily relate to your body fat. In fact if you are thin, the fat in the area may be more visible. It could be lymph nodes that are chronically swollen. If so, it is a medical concern.

Please see your General Dentist for clinical examination. He/she may want you to have further evaluation by specialist Oral Pathologist or Oral Surgeon. As what concerns you is bilateral, chances are it is not problematic.Go find out.