I totally get you. I don't think it's got anything to do with autism at all (does autism even include helping other people? I think it's coming off as being cold and anti-social because autistic people just are not good at social communication) It's because you don't want to hurt other people's feelings. Right now, if it's to the extent of even getting yourself into trouble, I think you need to set some time aside for yourself and try to be assertive. Set boundaries and if the people don't understand that, you're better off without them in your life. You've got a life too!