Properly speaking, the most close to the original expression English saying must be something like, "I'm sick of how much I need to do this!". As far as this saying (exclamation) always has ironical intonation in Russian, it really has the opposite meaning, "why must I do that?", "I really don't care about this" or something like that.

You may literally translate it as "need very much", but it usually means the opposite - I don't care about it. Often comes as a rude reply to request, for example: "You should apologise" - "Bolno nado (I'm not even up to)"

If it's used in question, you can translate it as "Do you really need it?". But if somebody asks you "Больно тебе это надо?", it means he think you don't need it. In other type of sentences it's like "I (somebody) need it very much", but with sarcasm.

One of the meaning - I don't care.

Nuance: It's not pain. It's an emotion of resentment and sarcasm. For example, when he took the initiative, but it was not needed. :P