The first thing to do is to see if you can get a more extended taper plan... although you need to be ready/willing to do it. Assuming you do want to (and realistically this is your only option), then print off the Ashton manual, which is the go to benzo tapering resource, and take it to your doctor, with your husband. Tell him you have been addicted to benzodiazapene and made mistakes, and want to taper off so that you can avoid the withdrawals, as they would set you back to square one, and run the risk of sending you to the streets in desperation (as has happened to a great many people). Request his help in this and request that he read the manual to help facilitate this. Ask your husband (assuming he is clean), if he would hold on to and administer the benzos, and be there to collect your scripts, so that you won't abuse them again. Propose this to your doctor - the point is to assure him, and also to ensure you stick to the plan. There is no reason you can't avoid withdrawals if you do a long taper.
If not, you will have to make do with what you have. It's not great but you can probably avoid the seizures. How many of the 25x 5mg diazepam that he gave you have you taken, and how much is an effective dose for you? Do you have tolerance? I tend to find that without tolerance, 5mg is mildly active, 10mg is half a dose - somewhat active, and 20mg is what I would consider a 'full' dose. Obviously, with tolerance this changes (and it is different for everyone), but you can usually work out what a dose is for you, and what a half dose would be.
So anyway, the point is to gradually reduce the dose. I think the worst of the withdrawal symptoms usually hit 72 hours after your last dose. Day three is when I would get brain zaps and start twitching, then have a grand mal... which is brutal, to say the least. IME it can be helpful to try and reduce your tolerance slightly, and it will also mean what you have will go further. The best way for me is to wait around 48 hours before dosing again. Nearer to 72 means your tolerance will drop even further, but it also means that you're approaching seizure territory and will experience some nasty withdrawals, so it is best avoided unless you have serious tolerance issues. Regardless, the basic method is to keep gradually reducing your dose, and aiming to keep things on a gentle plateau, rather than getting a full 'hit' from the diazepam. You would take half your usual dose, once per day, and then gradually you would reduce it to half that, then half again. For somebody who is benzo naive (i.e no tolerance) the method might be to go from 20mg, to 10mg per day for a week or two, and then 5 mg per day, then maybe 2.5mg, then none.
If things are tight by the time you get to the end, then maybe you would want to keep a final 5mg diazepam for three days after your last dose, which can kind of lessen the impact slightly but stretching things out a little bit longer.
These are just general musings and you will have to arrange a plan for yourself. There are people more experienced/knowledgable than me who can offer advice. I tapered off high dose xanax/etizolam powder last year, and with a gradual diazepam taper from the doctor I came out of it feeling better than when I started taking them, with minimal withdrawals. That said, I did have seizures when trying to reduce my tolerance with the powder, but that was generally through silly mistakes, such as using up the last of my supply and finding myself unable to get more.
I hope things work out well for you!