Oh library it's nice to hear when people are going through the same thing!!!! You have that feeling of thank fucking god, it's not just me!.
I love my dd to bits but I honestly questioned 3 or 4 weeks ago if someone had swapped my once contented, smiley and happy child for a winey, clingy, miserable little brat. That sounds harsh but honestly I felt like I was going to crack with how she was. Nothing I did was right for about a week (put her down, cried, picked her up, cried, put her next to me, cried, nursed her, took some then cried, repeat x 1000 in 24 hour period!) 
The last 3 weeks have been easier because I basically said right, it's a phase, she'll grow out of it, she isn't out to purposely "piss me off", she's a baby and she needs lots of love. I also resigned myself to the fact that I'm not going to get sleep either and to be more selfish with housework etc and catch up on my sleep during the day or go to bed early. So my expectations are low. If I get sleep its a bonus.
If you can, do anything you can to get him to take his naps. I ended up going to bed with dd just so she'd nap (and i would too). I also fed her to sleep too as it made more sense that battling it out with her for hour for her not then sleep I could noticeably tell the difference between night time sleeps with or without 'good' naps during the day. If she didn't nap, she'd turn in a different child at night!
Teething - I have never been one to give calpol at every murmur but i have given calpol quite a bit in the last few weeks. She's quite clearly in pain (you just know their cries don't you?) and just having that bit of pain relief before bed, has made things more manageable. I've found ibruprofen has been more effective with teething pain than calpol and dentinox is good too.
Use distraction - going out has been easier than stopping in. Walks, park, shopping, visiting family in a different house - all new stimulation which tires them out!
The last 2 days my baby is back - she's been ace and really happy- its like she knows I'm here for her and that she has appreciated what we've done for her (that sounds daft I know) We won't let her cry it out (have never done cio or cc) and she trusts both me and DP to be there for her. She's started saying mama now and has become even more cuddly than before which is lovely, especially with DP. She last night even went to sleep without me in the house (fell asleep on DP & he transferred her to cot) - that's huge and the first time ever!!! Here's hoping this lovely bit lasts forever 