Hi
It's often about this age that things can go a bit awry, and it's only worse if they're teething or learning new skills (crawling, walking by any chance?).
I think you should only cio if that's what you've decided will be best for you and your DS, at whatever age that may be.

Personally, I'd ride it out. At that age DS was teething and waking at least 5-6 times. Once those teeth finished at 11 months, things were heaps better. I was working too, so really do understand how hard it is. Can you get a bit of catchup sleep on the weekend at least? Do you cosleep at all - that's the only way I was able to survive. Oh, and if it's teething that's distrupting sleep, you might want to try an amber teething necklace. I wish I had gotten one when he first started teething...it has helped sooooo much.

all the best