I totally understand how you feel. I've had this problem all my life because I have a very compassionate and empathetic nature. Mostly this is a good attribute to have, but there are definitely times where it's been a real negative for me. There have been a number of times where I've ended up fighting other people's battles (often with a mutual friend), only to have them skipping off and leaving me hanging out to dry. Consequently I'm the one who ends up the loser, often times losing both friends.
Other people never seem to have a problem telling me the complete ins and outs of their problems, but when it's my turn I tend to gloss over things because as soon as I start talking I feel like I'm just a whinger. Plus the other person never seems that interested in listening to me anyway. So to all my friends I seem to have this happy-go-lucky personality, but that's basically because I don't bore them with the details.
Now at the age of 56 I think I'm finally learning to harden up a bit and let other people sort out their own problems. It makes me feel bad because I can always put myself in their position and think how would I feel, but I'd rather that than having the stress and anxiety of taking on their problems for them.
Dulciana I'm not sure what to suggest, except maybe next time you could listen to them and then make comments like "that must be really hard for you", and "I hope you are able to work out a solution to that", but don't take on the problem yourself. People have to "man-up" and become adults, and being an adult means sorting out your own mess.