I need help with my friends

For almost 6 months now, without asking, I've become the typical psychologist friend in my group, the one everyone vents to about their problems... but now it's becoming heavy and anxious, also because I'm a person who tends to absorb other people's pain, and so let's say this thing is starting to stress me out, also because I try to always be there for them and help them, but sometimes I can't help them, and it's stressful and frustrating to see that I can't do anything but stay close to them... what should I do?