I agree - get a second opinion

I don't know where you are, but in Leicester if you can't get an appointment soon enough with your own GP, you can go down to the infirmary to see one of the duty GP's down there.

If I ever needed a second opinion that would be where I would go.

And if I wanted a third I'd do it again on a different day at a different time.

3 is definitely enough if they all say the same thing.