Firstly i would seek a second opinion - i highly doubt that absolutely nothing can be done whatsoever about the scars, even if the focus is more on reducing their appearance or helping you to cover them more successfully - surely that's better than the current situation?

I'm not of the belief that tattoos are always the best option - they suit far fewer people than the amount who have them. Also, if the scars are that bad, there's no guarantee that a tattoo would particularly help with their appearance. Sometimes something that's been obviously covered up looks worse. Hence the reason why i think it would be better to go to another professional, see what other treatment and/or camouflage options are available and then decide from there.

As for your mother, the fact that she's ashamed to be out with you reflects very poorly on her. Seek out those who are more worthy of your time and affection.