Swollen gland in my neck. Heat or ice it?

Neither. You have to have somebody determine what they are. Swollen lymph nodes are from infections, usually. Muscle hard spots are just that. Swollen salivary glands are another thing. Have it looked at.
Alternate both. There is not really a good answer, you can alternate both, but the most important thing is to know why they are swollen, if that because there is a soft tissue infection or cellulitis around it or something else. Swollen glands respond to something for instance a viral infection, so the question is why they are. If you continue with swollen glands, go to your doctor for further work up.