Effect of lump sum capital payment on ESA benefits

I am shortly expecting a deferred lump sum payment of £90,000 from my matrimonial settlement which has been secured as a percentage charge on ex wife's property which was purchased 4 years ago with the sale proceeds from our Matrimonial homebut which she wants to pay off. I know that if I keep the money I will lose all my ESA and HB benefit entitlement - for how long?
Q 1
My ex wife wants me to forego the lump sum I am due in lieu of maintenance for the children which I have been unable to pay as I am disabled. I could only consider doing that if my benefits would not be affected. Is there a risk I will be deemed to have deprived myself of capital and have my benefits stopped anyway if I agree to this?.
Q2 I would like to spend the money on buying a property for myself to live in (my parents would fund the balance and own it jointly with me)- is there a risk that if I do this I will again be deemed to have deprived myself of capital and lose my benefits and is there a time period during which I have to do this? (I believe there is a schedule allowing 26 weeks- would that apply and what are the conditions.

I absolutely agree with Gordon's advice. Getting this wrong could have disastrous results for you, you really need to see someone who can go into this in depth for you.