Like you Emmz, I've been through it too, both with my mum who thankfully survived her suicide attempt but I'm afraid my Uncle didn't. I was only 13 when my mums episode happened and at that age I never got to understand her state of mind. She never spoke of it again, but the impact on me has carried through to today, and will probably never leave me. Its the feelings of abandonment you see. As a teenager I was very needy, and more than likely a bit of an attention seeker. As an adult its been better especially since I had my own children, but to cut a long story short one of the effects is that I get really anxious and twitchy if anyone is late coming home, or lets me down. I've learned to be more resolute about these things and have diversionary tactics to take my mind away from the issue but the underlying anxiety will never QUITE go away.
Hard to talk about the impact of losing my uncle. It took me years to accept that his choice was nothing directly to do with me and was completely out of my control. Some years later, as a result of both mum and uncle I became a Samaritan volunteer (for 14 years). In my mind I figured that if I could help just two people then it was a sort of recompense. As a volunteer with that wonderful organisation, you never really know who you've actually helped. All I know is by just being there for people to talk to when they are low is as good as anything.