These Three Things I Lost: 80 Years, my Desire and One Ring

[Boromir88]

Anyway, Gollum is at sometime captured and tortured by Sauron, then captured and pampered by Aragorn and the elves~alatar

Well pampered by the Elves perhaps, but Aragorn admits to being far less kind in his treatment of Gollum:

"He will never love me, I fear; for he bit me, and I was not gentle. Nothing more did I ever get from his mouth than the marks of his teeth."~The Council of Elrond

Anyway, as to the question of what was Gollum doing for those 70+ years. Hmm, interesting question, but afterall he was Frodo's guide through Mordor, so maybe he spent those years getting himself continuously lost?