I'd like to welcome you here to the Forum and know how hard it can be to simply relate what has happened and how it has affected you. Still I'm sure it will be worth it, reaching is very sensible.
Dealing with the suicide of a friend is one of the hardest things a person can do in their whole life, and there is no timescale. It can seem like yesterday because the greif, frustration, guilt and all the rest remain fresh. It is so much worse because you were in contact and did not believe - which really is quite normal. Suicide is outside our everyday experience, and therefor very hard to accept as a real danger..
While I'm sure it is true there is little point in reminding you that you could have done nothing anyway, you already know that.
Some people are luckier than others and in time come to terms with the event, and while never happy about it reach the stage where it is not constantly resurfacing and making life so upsetting.
It's sad you have not found the right people to support you, can I suggest if you have not already done so you seek professional support? Your GP should be able to locate a psycologist or councilor who has experience helping people who have been affected by someone close to them taking their life. Having that experience is important.
As for moving near you family, settling down and all the rest. You most probably are not ready, and there is nothing wrong with that. Going down that path just because others expect it would be a real mistake.
I think you will end up living how you want. You are a warm person who has had a great tragedy and simply need a little help to come to terms with things and then when ready make the decisions about your future life.
Can I suggest when you become depressed over this to use a help line? The Suicide Call Back Service (1300 659 467) is there for people just like you and can be both sensible and a comfort. It is no big deal to ring.
I'd realy like it if you came back and talked some more