I have spent years changing.
I was a willing doormat and happy to help others, I didn't expect things in return. I was very sarcastic and PA though.
I worked on trying to be a better person to stop sarcasm and make myself happy. I haven't achieved this. I have had various parts of me go from one extreme to another trying to improve myself. For example being very sociable to almost a hermit.
I am now going through a stage now of not wanting to do things for others at all anymore. I am still feeling bad for them. I am not feeling guilt or changing my plans for their guiltrips.
I even said "nobody did anything much for me, why should I feel bad" as an excuse to not do something. 
I want to be me and I am fed up looking after others I want to put me first now. I have as I cared for my family of origin my then h when married and children. They are now nearly ready to leave home. I don't need to look after people anymore and I am fucking relieved.
I really need to self care. I am fat, unwell, unfit and not making the best of life. Is this how I finally achieve self care? I did take care of my figure, health, looks etc in the past on and off. I would be horrified at my life now, ten years ago if I had time travelled.