caulkhead I've come to realise the healthiest way to exist for everyone... everyone .... is to balance your needs and theirs.
It's ok to value yourself as highly as valuing them. Sometimes some people's needs have to come higher for a while (children!). The scales tip then for a long time, though you still need to take care of your own needs. But it is not healthy to put yourself last - not for you, not for the people around you either. That's when your own unmet needs grow and mean that actually, you don't have as much to give other people. When you value yourself in a healthy way, you have more to give.
Sorry if that sounds like crap, it's difficult to think how to phrase it, but actually it's true.
Practical example: where I live in the NL there is a charity I work with that works with people who are in extreme poverty (the social security system is good in some ways but very tight in others). The charity mostly gives out essentials - nappies, babymilk, a second hand cot, a 2nd hand mattress, second hand babyclothes. But every 6 months if they can, they arrange childcare for the kids and send the mothers to an all day spa. They've found that actually, giving the mothers time for themselves means they can cope better with their worries and therefore with their kids; more patient, more time with them, less stressed.
Im wittering on but I hope you get the point .. trying to say that it's ok for you to put your own needs first for some time, as long as it's not actively at the expense of other people. Which it's not.
As a mother with MS, was your mother desperately short of help and support from family / friends / authorities? That could be why she leaned so heavily and frankly selfishly on you. Her actions then were a good example of someone who is taking care of herself but at the expense of others-you. It's ok now to take the time YOU need.
Hope you're having a great day in Bath and that it's sunny. Such a very lovely place!