Hi there
I have a 12 month old DD who has only ever slept through 6 or 7 nights in total in her life, so I can understand where you are coming from. I posted elsewhere on this board for advice because I have basically slid into the habit of co-sleeping in DD's room all the time (from about 11pm onwards) in order for us all to get a 'good' night's sleep.
I am usually a bit tired, but definitely not the same exhausted I was when DD was younger ( I would re-settle her in her cot, which, for a period of about 6 or 8 weeks would take 2.5 hours - this was when I had not long returned to full-time work, so I was a total crank all of the time!).
My DH says that I am generally a bit crankier or more easily annoyed than I ever used to be, but most of the time I can keep sunny, but it is not easy, and it must be doubly hard for you coping on your own.
Grandma has looked after DD overnight for 6 or 7 nights in total over the past few months and says she doesn't mind getting up in the night (whether this is true or not, I don't know), so maybe a very kind-hearted relative or friend could give you just one or two nights' sleep which would help you out in the short-term.
Eventually all little ones sleep through the night, even the ones who never did for a very long time, but it can take many months for this to happen. One of my friend's little one didn't sleep through til they were 27 months old - they used to leave a little sandwich and a drink out for them to get them through til morning. Another friend had a baby that was the WORST sleeper ever (up 5 or 6 times a night for 1 hour plus each time!!) - the mum developed epilepsy from lack of sleep, or rather the lack of sleep brought it out in her - but 'magically' the wee one suddenly started sleeping through when they moved house - go figure!
So, just so you know, you are not alone. I am a coward for change re PD / wi/wo and am having my own battle as to whether to really go for either of them, but I do believe they are amongst the most humane methods of teaching your wee ones to sleep through the night without you, bar riding it out till they reach their own sleep maturity (which could be as late as 4 yrs old or so).
Other ladies on this site have far, far more experience than me on PD etc - if you are going to go for it, they will give you unending support and advice.
Best of luck!