It's nice that you wish this sort of person relief , but really they're already finding it - by dumping all their crap on you ! I have a theory that this kind of person actually lives longer because they're busy purging themselves on the rest of us.
You really could be sending out the compassionate vibe that is very nice , but also like a beacon to this kind of encroachment. So you might want to investigate that , and think deeply on the matter of if you unconsciously believe you might be obligated to cooperate with taking this in to give others relief , or make sure on your innermost level of not feeling deserving of this kind of spiritual victimization. One also has to feel empowered and ok to defend oneself. Some people just don't .
Also, it pays to remember everyone has one or more OFF buttons. You just have to find the right ones. For example, my sister might decide to invite herself over. A simple explanation or a no will not deter her .(She is a soul sucking hellbeast that reason and politeness have no impact on .. ) However , if I say strangers will be coming over too, she will not want to come. I know this is a trigger fear for her and will shut off her intrusive actions .
In my extreme opinion, people like this are spiritual murderers . And they enjoy what they're doing on some level , so it's hard to get them to stop . One has to find a way to deprive them of whatever they're getting out of it . An old book comes to mind :
The People of the Lie, by M. Scott Peck
Another thing to bear in mind is that as long as you project sympathy , understanding , let's not make waves , I must not ever upset anyone, I have to save , help , elevate everyone and every situation spiritually , you could be at a very big disadvantage in stopping the activity and its' effects on you . It might be like leaving an unlocked door hanging open in your aura with the welcome mat out.