Well I'm another person who is going through the same situation as you too. I have the chronic sinus/ear issues. I just officially got diagnosed about 3 weeks ago, and have been on antibiotic and a special nasal rinse since then. They also sent me to vestibular rehab therapy for the inner ear stuff. They work with you on retraining your body to balance, your eye gaze, etc. I'm starting to feel a difference, but if all of this doesn't work, it may require a minor surgery on the sinuses. Which, if it will make me feel better, I'm all for at this point! I'm also working with an allergist/immunologist to try and figure out the cause, but so far we haven't found it.
When I went to the ENT, I didn't even know I had sinus issues until he told me, and confirmed with a CT scan. The ears were tested with a hearing test, followed by a test called VNG. There are also things they can do to specifically help the vertigo if you are experiencing that.
I also have a lot of separate symptoms from the ones I get from the sinus stuff (which like you is dizziness, vertigo, vision issues, headaches, fatigue). So I know I definitely have two things going on. They both make each other worse. It sounds like you may be in the same boat.
Hang in there. I know exactly how you feel. I also work at a job where I'm up all day and working with people, and have two little ones at home. I often wonder if other people can tell since I'll feel so off balance, or my hands are shaking as well. But, for myself I stay positive by thinking it could always be worse. I was so convinced for months that I had MS, this is like nothing lol. Just go in here in a couple of weeks, get your evaluations done, and be prepared to do whatever is needed. That's all we can do!