I have a 2015 Grand Caravan with 125k miles on it. Over the last month or so, I've had issues going uphill where my RPMs go up as I press on the gas, but my speed either stays the same or even declines. Last night was the worst instance of this. I just kept loosing power. I tried taking my foot off the gas to see if that would change anything, but nothing. It got so bad that I was at 4500+ RPMs going 20 mph. Typically, I'm at 3000 RPMs maximum. Once I got over the hill, I made it the rest of the way home with pretty normal speeds and RPMs, but I'm concerned as this seems like a progressive issue.

Also, I have two other issues that I'm not sure are related, but I'll list them anyway. 1) The car shudders a bit when going at slow speeds uphill. It goes away once it upshifts. 2) The first to second gear shift has seemed a lot rougher over the past week.

 

Hate to say it but sounds like transmission.

The RPM flaring (rpm increasing but no change in vehicle speed), and the shudder, could be torque converter not getting enough pressure. The rough shifting between 1st and 2nd gear sounds like the transmission A-B solenoid. Only thing you could try is a complete transmission fluid change and see if that helps. I don't mean just dropping the pan for a drain and fill which is what transmission shops usually do, if even. I mean drain all transmission fluid including what's in the torque converter. A good reputable mechanic will know, but they may advise that it's too late. Still, you should get a good reputable mechanic to take a look.

Good luck.