Truck Refinance Help

A year ago I was 19 and signed a $41,000 truck for 72months with 15.35% apr paying $900 a month (loan required a limited warranty and GAP insurance alongside). I sold my soul 🫩. I was young and stupid made a big mistake. I am well aware you’re going to give me a lot of shit.

On the bright side I have learned a lot about building credit and my credit score has shot up from 640 to 713 in the past year. I’ve been building credit accounts, using low utilization, and I haven’t missed a single payment.

So now I thought it was finally time to look into refinancing my truck finally, alongside cancelling the warranty. I plan on keeping GAP, due to having minor negative equity from majority of the payments going into interest.

For the truck payments alone without the add ons, I am paying $750. I have 60 months left of the loan. While doing the math though, I found disappointing results. I have been using 9% with the new loan as a place holder, so I thought the savings would be astronomical especially canceling the warranty. After doing the math though, $37,262 – 9% – 60 months – GAP, I would be paying $770-$775ish.

Finding out that majority of the payments go into interest for the first few years was not very pleasant lol. Although I can now cancel the limited warranty, I technically would be paying more from the $750 a month. GAP doesn’t really add much to the payment.

So the question is this- Do I refinance for the current 60 months, do I refinance for 72 months, do I do nothing, or am I just a kid looking at this entirely wrong?

The major concern of mine is that the longest credit term I currently have is my truck. Losing my longest credit line is going to damage me a lot, so I only want to do this if necessary. I would love to open another credit line as well, but proceeding with this would mean I’d have to wait awhile.