I'm in a similar situation (and I've been discussing it in another thread but no advice seems to be working). My problem is simply finding someone to feed on. I turned full-blooded in the middle of my conversation with Falion so I had to flee before I could set the quest in motion. Now I'm stranded in the countryside, hungry and alone, and everywhere I go everyone is awake. I've been torched about 5 times already. And I keep pushing on into the wilderness and find...nothing. Advice?
Pay a visit to either the Dark Brotherhood or the College of Winterhold.
I haven't found out for myself, personally, but I've read that both factions won't be hostile to you, even as a blood-starved vampire. You should be able to try feeding on them, though you'd best not get caught in the process.
I've yet to try it myself, but you can apparently keep a companion following you, and can just periodically command them to sleep in a bed and then you can just feed on them whenever necessary to keep from getting to the final stage of vampirism.