3 year-old's whining - normal, or anxious and miserable?

[OhBuggerandArse]

Difficult for others to advise on this one without seeing it themselves, I suppose, but I just wanted to run it past.

Am getting to the point with my three year old's whining where I'm beginning to think there's more to it than just his developmental stage - he whines, whinges, or uses a tragic sad voice about 90% of the time these days, and I'm worried it's becoming so integrated into his personality he'll never recover from it.

If you ask him (several times) to use an ordinary voice he can usually summon up a huge effort and manage after a few tries, but the next thing he wants to say is straight back into the realms of tragedy. Have tried being relentlessly encouraging and positive, and also trying to see if he can articulate if/why he's feeling rotten - neither very successfully.

In the middle of a baddish day of it yesterday I suddenly realised that if I met him for the first time just now I'd think he was a really unhappy little chap - anyone got any thoughts about how to steer him though all this and get my cheery jolly boy back?

Is there anything else going on at the moment in family life which is stressful but that doesn't necessarily directly involve him? The reason I ask is that my usually cheerful 3 years 7 months son is suddenly a total whinge-pot, all day, non-stop, cries if anything goes remotely wrong, cries if anyone so much as touches his arm and he claims they hurt him etc etc, he is totally defeatist about everything, feels he cannot do anything, feels it will all go wrong if he tries....the list goes on...he's just so miserable 90% of the time!!! And a total drama-queen about anything remotely that goes against what he wants.
So anyway, the point of telling you this is to say that his older brother, DS1 (6 years old) is going through some major health issues that will affect him long-term, very difficult for all of us to cope with..major surgery still to come etc. And I am convinced that the change in DS2 is related to all this. Firstly all attention seems to be on the ill child, people have been bringing him presents and magazines etc for having this horrible thing to deal with etc....life at home has changed as DS1 is in a wheelchair now....so DS2 must be feeling left out. I think his miserable whinging 24 hours a day is all to do with this. We have been trying to do more one to one stuff with him, less telling off for rubbish behaviour, more one to one playing with him etc.....so far not much of an effect but wil persevere as do feel that it may help. Could this be anything like what's going on with your DS?