When you change, it’d better be because of something, rather than for someone. In all kinds of relationships there’s influence, and this usually becomes ground for resentment later, rightfully so, most of the time.
From my humble experience in life, I wouldn’t say that changing for someone is a bad thing in its entirety, but the benignant portion of that could always fall under a bigger institution; like friendship, marriage, parenthood or general care giving, responsibility and protection. If such an institution of human coexistence isn’t already manifest, then changing for one of the parties involved is usually a bad thing. If it’s there however, then even drastic changes are usually okay.
A piece of advice from someone who suffered a whole a lot in that department: search for that something, not that someone, and change because of it, rather than for them. Be ready for it, not them, so that if they disappear, you wouldn’t relapse! On a grand scheme, this would help you govern your life in such a wiser, independent way. Sacrificing for a single parent should always mean you have it in you to go the very miles for another, or even for an elderly person. It’s about the idea, not the persons involved.
This usually shows signs of pain when it comes to men and women, and marriage. I for one had made the mistake before of either changing for the wrong reasons, or asking others to change for me, while it was all after a bad turn; namely: no one valued the institution itself, the idea of it, as much as they valued themselves, so they never got ready for it, before they got ready for each other. It’s a very fine line, but it’s there. Like an umbrella. I think that’s why in religion marriage is such a sacred bond, it’s like a third party in the relationship that has its own rights, you know?
There’s something else I experienced, and I don’t know if it’s the case with everyone, but usually when I’m given the impression that I’m asking too much of someone, then it usually is a very strong sign we’re not right (or ready) either for each other, or for marriage in the first place.
A butterfly’s metamorphosis is a process that owes nothing to no one. The caterpillar doesn’t grow wings so that it could fly with another butterfly, but so that it could just fly, like the butterfly it’s meant to be. Of course, it could happen that she’d be wed to another, and then they can change each other in their ever-after all they want, but certainly not before.
Some things you ought to do on your own, preferably for God’s sake only. Let go of that waiting, and be ready.