This is going to sound bleak, and I've struggled with some nicer way to present it. The 'you' in this refers to both you and your husband.
In a full-scale Evac, you will (hopefully) come off last. The last thing that the crew need is for you to attempt to exit with all the other pax, as in doing so, you will temporarily block, or at least slow, the flow rate to an otherwise usable exit There is a good chance that if you attempt to leave earlier, you will be knocked over and trampled underfoot. The slides can accept you in any position - head first, feet first, face down etc. Any position away from the standard will not be comfortable, either at the time, or afterwards, but it will get you out alive.
Once down and at the foot of the the slide, your husband can be dragged (hands/belt/jacket) by somebody else away from imminent danger. Crutches are not essential for life, and carrying them represents a significant hazard to others, as well as your husband, in the cabin. The odds are that in the fast descent and then sudden slowing on the slide, the crutches being carried would fly loose and could injure otherwise fit people assisting at the foot of the slide.
We would expect you to assist and take responsibility for your husbands exit from the aircraft, but, if possible, we would assist you. The central driving concept behind an evac is 'Greatest Good for Greatest Number' - CC need to be focussed on maximum flow rate out of the doors they are manning (womanning?) to the exclusion of all else. Once down the slide, somebody will help you at some point.
In a catastrophic evac, the pilots will usually exit by the forward doors, or even by the flight deck windows. Crew are instructed to check the cabin area near their doors if possible before leaving the aircraft.
Smoke and heat may well be your greatest dangers. If there is smoke, while waiting to get out, cover your face and get low. Headrest covers, blankets, pillows will all slightly slow smoke ingestion. The floor has illuminated lights that, if crawling, will lead you to, and then indicate, the exits.
In a ditching, all of the above applies, however your lifejacket will stabilise an incapacitated or disabled person in the correct position once in the water. The light on the life jacket helps others in the sliderafts to locate people in the water and therefore to pull them into the sliderafts.