Erm - I have one of those 2 (6 month olds that is) and he is very similar atm, slept OK for his first 5 months but hasn't slept more than 2 hours at a stretch in about 5 weeks, and is more clingy in the day - it's not just teething, though that is part of it, there is a huge amount of emotional, social, and physical development going on at roughly 6 months and they have a lot on their minds :)
I feel like the living dead some days, as I have 2 older ones who need to be up (and need me to be up as DH leaves for work at 6am) very early as where we live the school day starts early and finishes at lunch time - then I need to supervise home-work and friends 'round to play and a couple of extra activities etc. - all the usual stuff, in the afternoons...
Only words of reassurance I can offer, from the perspective of someone going through it but who has gone through it twice before, is that this phase will be over very soon and then you will have a baby who is a bit more of a little person, probably with some new skills and that bit more interactive and communicative - DS2 is sitting securely, clapping and reaching up to be picked up now, which are all new milestones, and the achievement of which has probably had his brain buzzing and whiring, and caused frustration in the day as he tries to get things sorted!
Separation anxiety also really kicks in at this age, partly due to advances in social and emotional maturity - again it will wane and things will get easier, but it is hard to know exactly when!
Meanwhile, have some 
, but don't fall asleep drinking it :)