Generally we are who we are because of our personality and experience rather than from choice.
I won't stop being kind and thoughtful because someone treats me badly because I won't let them dictate my behaviour
However being kind and thoughtful does not make me a walkover - I am also assertive. I am happy to ask others to help me as I am to offer to help them.
I will say no if a request is unreasonable or I have a different priority at this time.
I will try and help someone find a solution rather than just taking over if they are struggling.
I come up with ideas to help solve problems and I don't get upset if these ideas are not taken up because they are ideas not advice.
Generally I don't find people to be rude or unkind. Sometimes people seem thoughtless, because they have their own priorities which are not mine.
If I ask someone to do something and they say no or make an excuse I accept that and am not upset. They don't have to help me and again they may have a different priority.
Some people do try to take advantage. After not helping me when asked they expect help. My response, the first time, is to say, 'well I can do 'x' but not 'y' as I am still behind from not being able to get 'A' finished yesterday.
If it happens again the response is 'No, sorry I can't not this time', which will be repeated until there has been a change in their support of me. or others.
Probably won't work in every situation but it has worked well for me most of the time