I agree go back to your GP, explain you were unhappy with the dismissive attitude. I too would have thought at the least you'd have a proper manual examination and possibly a mammogram given the circumstances. Any hospital unit has a number of consultant breast surgeons, so it should be entirely possible to be seen by someone else.
I would go back to your GP and explain to them your concerns. They sounded on the ball by
giving you an urgent referral.
Ask to see another consultant. I saw a consultant once and refused to see her again, you have that
choice, afterall it is your body.
I don't think you are misusing the NHS that is what it is there for.
I hope your mum's results are clear.