Oh it is really sad to you tommypickles blaming the child being for being naughty or having something wrong with him and that he needs to be good. He is clearly unhappy and he sees something wrong in his life. He needs to learn to deal with this and perhaps ofstedoutstanding can help. You could be the one important person in his life who could try to understand his perspective- whatever that is.
Yes part of his crying might be to get things that he physically can do himself but for a child to feel so helpless and cry all day they are clearly comminicating how they are finding life difficult. That they don't feel in control of their environment. He is directing his crying at things e.g. drink, buggy, but that is maybe to make sense of his persistent need to cry/make noise.
Surely he needs to be made to feel secure- this totally includes sensible boundaries but he needs to calm down and be happy inside himself not because of external rewards. Has the nursery also noticed anything?
My initial instinct from what i have read is that he is lacking significant, consistent and positve one to one interaction/attention, perhaps at home.
Make sure he realises that you have noticed how upset he is, tell him calmly that he must feel really unhappy to cry/shout/whatever so much, that you can see how he just really wants you to help with whatever. i would say all this quite a lot in different ways. He is still young and it will help draw his attention to how he feels/is being but in a non-threatening/judgemental way. As an experiemental short term measure I would try to anticipate what he wants before he cries about it too long and give attention/affection when he is not 'asking'.
If you feel you and your family can't cope with this (it is clearly upsetting you) you should absolutely not continue but if you view it as a challenge for a few more months it might be really rewarding if you can support him through it all.