I'm very near the end of paying back all my debt. It was about £9k total, 18 months ago was down to about £6k and now it's down to just under £2k. My debt costs me £370 per month. Knowing that I've got just months left of paying it off, this month I gave myself a payment 'holiday' by just paying the minimum amounts, so that it could spend some money on winter boots for the three of us (me and dh had leaky shoes last winter) clothes for dd (no winter clothes that fit) and some thermal curtains for the house (I refuse to sit and watch our curtains blow around when we've got the windows shut again).
I understand your predicament. When the prospect of being debt free is so far away, the chance to spend money on yourself without feeling sick with guilt, I know how it feels to want to do something that feels nice.
If you're doing something constructive with it, then why not? However, do make sure you weigh that up against how you'll feel holding onto your debt for longer.
We have 2.5 years until dh's personal debt is clear. But we needed to spend some money this month - if only to remind us how we'll feel when we can spend like this every month. If we wanted to that is, we wouldn't because we never want to be in that much debt again. At its worst 6 years ago we had £40k on cards and loans.
Have you looked at someone like Think banking? Dh has a debt management agreement with them,through a debt management consultant. Yes, that's costing money but we weren't disciplined enough to do it on our own.