lots of reasons whey they "can't" do something. At times I feel like I get sucked into their problems or most likely manipulated.
I think I know the kind of people you're talking about. If people aren't willing or able to accept responsibility for themselves the other side of the "medal" is normally that they project responsibility for their own well-being onto their environment, in other words they manipulate people in their surroundings towards feeling responsible for them.
It's important to understand that you are not responsible for other's people well-being. If you wish to help them, it's important to help them help themselves. Especially in Buddhist Centres some people try to appeal to others' Bodhisattva attitude and make them feel guilty if they don't give them what they want. But sometimes giving people what they want is the opposite of helping them.
If the only way for you to protect yourself against being manipulated is to keep people at a distance, then that's what you have to do.