Did you give it B-1 when you repotted it. Plants have transplant shock and B-1 is the cure. Did you water it too much? Plumerias like to be dry and somewhat neglected. Did you mix pumice and/or perlite with your cactus mix (some are way too moist and organic for me.)? The good news is that even transplant shock often does not kill Plumies. They are very hardy. But do not do too many new things at once, Where is wildcat when you need him. He had a 7 foot plumeria grown near Chicago and had a wealth of how to survive the winter info. I think there are some successful members who grow in Denver, so all is not lost. You did transplant too soon. I wait at least one year. A 2-3 foot stalk can do fine in a one gallon pot for a year. Pray and believe that your plant will pull through. Seek info on how to overwinter a dormant plant which will drop all its leaves and go to sleep (No water needed or just a cup a month until March) Then you can watch it rise from the dead.

I didn't do any of that... what should I do now? Should I add the B-1? Should I leave it be? do you need to see photos?

Thank you so much for your response.

Stick your finger deep along the side into the soil and determine how moist it is. If not too wet, a dose of B-1 would help. If moist, let it dry. If very wet, dig the soil along the outside of the pot out and replace with faster draining soil. use a large spoon.

it seems to be drying out better now... There are suddenly two new leaf sprouts. I fertilized it when i repotted it. What is B-1? will it react with the fertilizer poorly?

I very much appreciate your help!

Wow, What a great story of how you discovered the Plumeria. Brought tears to my eyes. I have recently gotten quite hooked on them myself and have asked a number of questions on this forum. My most recent was about fertilizer, and I got a great response from someone. I'm going to put it here for you. Good luck with that Plumeria of yours. They do seem to be pretty hardy, and the fact that you have new leaves sounds pretty darn promising.
Here is the response I got about fertilizer. Hope it helps
Lauri

A lot of people (including myself)use a "super bloom" fertilizer that has a ratio of somewhere around 10-50-10...A high middle number is key...Different people use different brands, and I've learned that fertilizer in liquid form is the best since it is completely dissolved (verses powder form or extended release) I feed my plumies once every two weeks, and I ALWAYS water my plants first, before feeding them the fertilizer. If you feed them with the soil dry, you can burn the plants/roots...A lot of people also spray their plants with the fertilizer, but I've found that feeding them at soil level works just as good for me... Once September/October rolls around, I'll stop feeding them the super bloom so they can prepare for dormancy.

I also read on here that they shouldn't be watered through dormancy, maybe just a cup a month.