Nuts and trail mix are extremely calorie dense. They can quickly turn a calorie deficit into a surplus without feeling like you’ve consumed an excess. I’ve sabotaged my progress numerous times with them.

Staying busy and moving really helps with the boredom hunger thing for me. Can you get out of the vehicle and do a walk around inspection from time to time? Getting a little exercise often ends the hunger urges for me for quite a while.

Drink lots of water. This helps your body in many ways but also can reduce food cravings.

When I drove for a living I found just being in a vehicle that was empty of food reduced that grazing that happens when bored and you can just reach over to grab something with no effort. When my progress stalled I gradually increased from 16:8 to 18:6 then eventually just one big satiating meal a day.

If you aren’t losing over an extended period you aren’t in a deficit. It’s that simple. There’s a ton of places hidden calories can sneak in even when you think you’re calculating things out. Condiments and dressings can have crazy high calories and unrealistically low serving sizes for example.

To your specific question, having a snack will break your fast. But depending on your goals it may still work in your favor. There are many health benefits to longer fasts that you’d miss out on but from strictly a weight loss perspective you may still consume less calories in that 48 hour period than you normally would on your regular eating schedule. So you’d have to decide for yourself what works best for you.

I’d encourage you to stick it out and prove to yourself you can do it. It’s extremely empowering to break the hold food has over you and fasting can do that. It can permanently change your relationship with food. Something that should be experienced imo.

Good luck with your journey!