Hi Euromum
You could try this technique, which worked really fantastically well for us. It's called the Kissing Game. The basic theory is to remove the fear that he may be feeling at being alone, and allow him to get over his anger by himself. It goes as follows:
You run a nice soothing bedtime routine. Then you put him in his cot, give him a kiss or stroke, and say "I'll be back in a second to to give you a kiss" in a good strong positive voice, wander over to some point elsewhere in his room, and then come back to the bed a few seconds later, give him another stroke, and then wander away again saying the same thing, and come back again, and so on and so for. Think of yourself as a yoyo, in constant movement. After about five mins, you carry on with the same movement, but pop out of the room and then straight back in again, and then you slowly start to stretch out the gaps between going out and coming in. Meanwhile, he's likely to be getting really quite cross and crying -- you ignore it all and talk away in a nice positive voice. He knows not to be scared because he keeps on seeing you, and the rest is just a battle of wills to get you to pick him up, which you can win through unfailing positivity!
After about 10 mins, you should aim to be stretching out to about 30seconds between kisses. We are a bit odd in some ways and found it reassuring to use a stopwatch and methodically add on pre-planned extra time (10 seconds, then 15 seconds, etc) as it made us feel more in control. After a good old while -- maybe as much as 40mins, he will eventually get knackered and lie down, at which point, you want to stop talking but keep on popping in with the kisses. Our DS always sounded jolly humphy when lying down at this stage! You carry on stretching out the gaps between visits until magically, at some point, he'll fall asleep by himself. Then you shut the door and pour the wine for the toast!
The next night, you do it all again. Our pattern was that the first night was horrible (three or four hours, hundreds of kisses, absolute fury on his part at our outrageous behaviour!), the second night marginally better, the third night pretty good, and then the fourth night, it felt like we were back to square one -- but it was a final shake of the fist, as it were, and the fifth night there were no tears and it was over really quickly. It took a couple of weeks to get the habit solidified, and then it worked fantastically for ages (until DD came along.....). There were some night wakings along the way, which we dealt with in exactly the same way. As we progressed, we were also able to move more rapidly to longish (say 1 to 2 mins) gaps, and by the end, we would be able to put him down and walk out of the room for 2 / 3 mins, come back once, and then know that the next time we came back, he'd be asleep.
BTW, I don't think the technique would work well if he still wakes for fluid at night. We had to break that habit first.
I don't want to pretend it's easy, cos it's not the crying is wearing. But the advantage of knowing that he's not scared just cross was that it made the crying much easier to deal with! Another faintly odd thing we did that helped us, was to keep a notebook of progress, where we noted the time we went out of the room and the time we went in. It helped us stay objective about how things were going sometimes it would feel like we'd been at it for an hour and it had only been 10mins, for example.