Agree with all @Spinningonthatdizzyedge has said and it sounds like you're conflating two solutions as having more than £75 a month wouldn't stop you from going bankrupt if your debts are unmanageble and you can't pay them off in a reasonable timescale, eg if you have £150 pm available and you are £20k in debt. If you went bankrupt, you would be subject to an income payments order, and would have to pay towards the debt for 3 years.
I've quoted my previous post because you need to look at your budget to make sure it is sustainable and the MSE DRO bankruptcy forum will help you do this.
When people struggle with debt, there's a temptation to cut back on essentials to pay their debt, which is the wrong way to go around the problem, especially if the debt has arisen because you've been using credit because your income doesn't cover your basic essential living costs, rather than enhancing your lifestyle beyond what's affordable.
To get out of debt, you need to set a sustainable budget, which means you can buy sufficient food, other essentials like toiletries and cleaning products and other sundries like batteries and shoe laces from time to time as well as paying all your bills and even having a modest social life. Then you use what's left to pay your debts.
If you rent, your best solution will almost certainly be one of a debt management plan, a DRO or bankruptcy, depending on the amount of your debt, your surplus and how long it looks like it will take to pay off your debt, also if you expect any change in circumstances such as a promotion at work or reduction in childcare costs.
But if it looks like a debt management plan will take more than around 5-6 years to pay your debts off and you don't foresee a significant improvement in your finances, that's when a DRO or bankruptcy would be recommended.
As a non homeowner, an IVA would only be recommended if you are in one of a minority of professions where you couldn't do your job if you were bankrupt, but these are quite rare and if this applies, your employer, union or professional body will probably be able to give you access to free advice and support in relation to getting out of debt.
Nationwide Partners are almost certainly pushing you down the IVA route because they make thousands of pounds from you doing this.