Desperation - sleep help?!

We are starting to get a bit desperate now....Oli hasnt slept through the night for months. A normal night looks at lot like this:

Bedtime - 7pm ish, then first wake up crying a couple of hours later. A cuddle works and then he settles back down. Then he wakes somewhere between 1.30 and 2.30am and grizzles and cries on and off, if we ignore him then he keeps going and going, and if we go into him then he revs up more, if we pick him up he screams and it takes ages to settle him. We have been resorting to giving him a bottle - out of desperation - and now we are trying to wean him off that, but its hard going. Its getting really hard on us to lay in bed and listen to him grizzle and cry for hours at a time.

I just dont know what else to try....he wont have a lot of his bedtime bottle, so he may well be hungry, but we cant seem to get him to take more of his bottle no matter what we do.

Although DH and I take it in turns (he does one night and I do the next)...somehow DH manages to sleep through the crying when its my turn, but there is NO way that I can sleep whilst he is grizzling. So we are both knackered, and its getting a bit tough. Any suggestions hugely appreciated!!! 

Thanks for the suggestions guys. He has been sick on and off for the past few months, with colds and an ear infection, but he seems well now. I cant feel any teeth, he has 8 and I dont know which ones come next...will have to check the rusk box!

We are willing to try all sorts of things now....its just starting to take its toll on us, so we need to sort it out. I dont know what to do about his daytime sleeps....I think maybe he is sleeping too much, but if I dont put him down he gets overtired and grizzly. He currently sleeps like this during the day:

after first bottle of the day (aprox 6.30-7am) he goes straight back down until 8.30-9ish

morning nap - about an hour - at 10.30ish

afternoon nap - normally about 1430-1500 ish for another hour

(its all been thrown out a little bit by daylight savings - like he is down now for a little nap, as he was giving me all the tired signs....)

The only time he sleeps longer than an hour, is after swimming, I havent been able to get him to have bigger sleeps, but not sure that would help anyway.

Simsam, just as an example, Tom's routine was something like this.

7am: wake

7.30: breakfast

9am: bottle then back to bed for 1.5 to 2 hrs

11.30: lunch

2pm: afternoon nap 1.5 to 2 hours

5.30: dinner followed by bath

7pm: bottle followed by bed.

Well, at least thats what he was doing till this week.  He was very happy in this routine. It may have shifted by an hour either way or so but always the same time gaps.  Its all turned to sh*t this week though