For the AC not working, some of the remedies discussed in the Escort ZX2 thread apply. Also, there was a stepper motor on the blend door on the evaporator box that was an Achilles heal for that year series.
If it is the compressor, you can get that at most auto salvage yards for under $80 with a short warranty and a bit more with a 1 or 2 year warranty. Search
www.car-part.com for who has one near you.
And don’t forget to negotiate for lower price. Those compressors are very plentiful and supply outruns demand. So you can use the info on car-part to leverage one yards availability against another’s price to get the deal you want/deserve
And the crash sensor that
@Zeldman pointed out was almost always the reason for the bag light. Sometimes the air bag computer, but rarely. Someone good at electrical system diagnostic can quickly point out the fault. Rockauto.com will have both items for reasonable.
~$500 might get these current troubles fixed. And then you can start an 18-month savings campaign toward the future replacement.
If your new truck was going to be $500/mo, then after 18 months you would have $9,000 in the sugar bowl, providing a good sum to go used truck shopping with.
And, if Mr. Murphey shows up and started stomping over your life with sharpened golf cleats, then you have cash (not debt) to clean up his mess and kick him down the road.