Lately, i've been feeling very tired/nauseous and have ringing in ears. have quite a lot of stress. could this be causing it?

It can: Its amazing (and unfortunate) what symptoms stress can manifest as - basically any symptom you can imagine. But diagnosis like that are ones of exclusion, as in you rule out more concerning "stuff" first and then are left with stress and/or anxiety as the only cause. You should see your doctor to make sure nothing else is going on.

Tired nausea tinitu: given the scant inflammation of variety of causes can be responsible, the common 1 is a disturbance in the middle year balance mechanism often accompanied by vertigo. Symptoms can need to anxiety, if persistent C a competent practitioner to exclude more serious pathology