Losing power on hills

Hello,
I have a 1986 Toyota pickup. It’s small 2 wheel drive with a stick shift. 6 weeks ago, it started lugging very slightly on hills after I had first started the car (only in the first 5 minutes of driving). Then that stopped, and now it loses power on hills so that I have to keep shifting down and going slower until I’m chugging uphill in 2nd gear at 30 mph. It only happens on long hills with a sustained uphill; smaller ones it keeps speed and power fine. Does anybody have any ideas for a quick (and hopefully cheap) fix? I’m driving across the country alone in a few days and hope the car will make it! Thanks, Kitty

When was the last time that the fuel filter was replaced?
How about the spark plugs and the air filter?

Before any serious diagnosis can be done, you need to make sure that the truck’s maintenance is up to date.
If the above-noted items do not remedy the situation, then you should have your mechanic check for a restricted/clogged catalytic converter.

Driving cross-country solo in a 25 year old vehicle is risky to begin with.
Attempting to do it with a vehicle that is not maintained flawlessly is…let’s just say…going to give you more of an adventure than you had counted on.

A few guesses are timing is off in the engine or you have worn ignition parts. Replace the distributor, cap, and have timing adjusted.

None of those items are expensive to fix.

I had a similar issue with my 89 Toyota Pickup way back when and it ignition/timing.