Honestly I don't think you have much to be worried about.

Aside from the airflow and filtration issues mentioned above, everyone on the plane is required to have a recent negative test, and I would presume that nearly 100% will also be fully vaccinated, as that is required for entry without quarantine to the UK or other places in Europe. I am assuming you are also fully vaccinated, of course.

If all of that is not enough to make you feel safe, then probably you should cancel the trip, as the plane under these circumstances is likely the least risky part of venturing outside your home.