7 month pregnant, suggest some solutions for mood swings and sleeplessness.

Seek evaluation. It is advisable to seek an evaluation with a mental health professional who specializes in pregnancy and postpartum depression. If you have Antepartum anxiety and/or depression (10-15% prevalence) it would be best to start treatment now to lower risk of postpartum depression and anxiety. Many ppl don't realize anxiety is often more common than depressed mood. If in IL, I can do virtual consult.
Agree w Dr Feingold. Retire & rise same time each day. Keep bedroom dark & cool & use only for sex & sleep. Turn off tv. No naps. Exercise regularly but not in late evening. No caffeine for 6 hrs before sleep. Keep dinner moderate sized & finish at least 2 to 3 hrs before sleep. Can try warm milk, Chamomile tea along w light reading, warm bath or lavender scent.