Can a sinus infection cause motion sickness?

Yes. The sinus infection and cause of it can lead to fluid or inner ear infection causing motion sickness.
Sometimes. The presence of any infection can affect your sense of balance and lead to dizziness/imbalance.

Related Questions

I have a constant reoccuring ear infection that causes frequent ringing. Leading to dizziness and motion sickness. What home remedies are there?

Ear infections. This is a serious problem that you should be working with an ENT specialist. Chronic infections can be quite serious, and home remedies are not powerful enough to cure most infections.
Osteopathic massage. Some osteopathic physicians know how to drain the fluid naturally through the eustachian tube. This gentle massage can be performed by a family member at home. It is a treatment I taught to medical students when I was a professor.
Not an infection. You are describing meniere's syndrome not an ear infection. Meniere's syndrome is classically defined as intermittent tinnitus, vertigo and hearing loss. In the absence of significant pain which does not let up it is most not likely an infection. I'd recommend seeing an ENT when you are symptomatic for a good ear exam and hearing test.
Menieres syndrome? Possibly but for it to be classic symptoms: 1) ringing in 1 ear 2) ringing is constant, there are never times when there is no ringing 3) significant hearing loss in that 1 ear, especially in the range of the spoken word 4) occasional or frequent bouts with vertigo. If you are diagnosed with menieres (cause is unknown). Significantly reduce your salt intake and eliminate caffeine which can trigger.

Can untreated ear infection/tooth abcess/sinus infection/gum disease cause lymph nodes in left supraclavicular? Any possibility?

Yes. Yes, the bacteria are activating your immune system and the lymph nodes swell when they increase production of white blood cells to fight the infection. Please get the infection taken care of.
Yes. The lymph system system in the neck is affected by the oral region. You should not ignore this.
Monitoring Centers. Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells and digested food. Lymph nodes "taste" the lymph for anything bad like bacteria/viruses/cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react. They shrink when all is well.