To answer your question, yes, i’ve wondered about it in the past and if I thought about it for too long now I would be unlikely to speak to anyone again !!
That was the crux of the matter for me not so much why did they do it but why did I tolerate it in what was once quite a self sacrificing way. They did it because I let them, is the short answer but the reasons behind all of that were deep within me and nothing to do with them.
If and when you are able to let it all go is more likely to be when you do not have active addictions in your life whose behavior serves on a daily basis to remind you of why should protect yourself from it all. You will let go when it is right for you. No guilt is required !
Trying to be mindful of your own needs is great as is trying not to rescue him from all the situations he creates for himself and far more beneficial for both of you, he can learn from his own mistakes and you will have a lot more space in your weary mind to start putting in there some of the nicer things in life.
Good one Madge keep it up