Hey M.,
Whew, you must be exhausted! I was having similar issues with my guy when he was about 5 months. A book was recommended to me that was extremely helpful. It's called "Solve Your Child's Sleep Problems" by Richard Ferber, MD.
Anyway, he has a very specific method of getting your child to sleep through the night by letting them cry it out for longer and longer intervals over the course of several nights. It's not easy at first, for you or for baby, but my guy was sleeping through the night in 3 nights flat and has been ever since (he's going on 9 mos now).
It goes without saying that every baby is different, but this really worked for us. He wasn't even eating solids yet at that point, just nursing, and it turns out, was completely capable of sleeping through the night. It was just a matter of disassociating the connection between nursing and falling asleep.
Maybe you can find the book at the library? I bought a copy at B&N because it talks about every sleep problem under the sun from sleeping through the night, to naps, bed wetting, nightmares, etc... so I figured it would come in handy for years to come. It's extremely helpful in explaining the scientific side of sleep, which helps make sense of the techniques.
I hope this helps! Good luck to you!