I would assume the reason why its important to take with food is due to avoiding issues like nausea, vommiting and ulcers. You may have to increase the size of your eating window to accommodate the needed medication. If its not something you have to do forever, then just keep reminding yourself of that as you take it.
If it were me, and im no doctor and dont take this as advisement, i would eat my food with my first dose and then eat 9 hours later so that 3 hours after that when that second dose is due, id still have something in my stomach even if its super low. If my body handled that well, id probably stick to it giving me a 15/9 fasting schedule.
Good luck with the nerve issue. As someone whos turned to IF given the weight i gained from nevre issues and bulged discs, getting that fixed should be your priority over IF and that is advised by me lol.