I think you did a fine job. it should start to wake up here in the next few weeks to a month and will push leaves and branches below the cuts. If the tip starts to rot again, which they shouldnt, just cut back like you did.

Ill will be honest I expected it to be much bigger for 7 years old.

Jen your word "frangipanic" has gone mainstream.

Mike

Thank you! That makes me feel a little better. I wasn't sure how to cut it as I've never done it before. I've kept her in that pot for the last 2-3 years with just trimming roots and changing fresh soil. I do not have room for her to get too big. She's always done well in the summer with beautiful huge blooms. :)

Those really are some lovely blooms! I know it's scary to see them in distress like that, it can be heartbreaking.

I agree with Mike's great advice, and just keep an eye on it to see if it heals up at the cuts. If you do end up having to cut again the only thing I would add is the sterilize your shears with rubbing alcohol in between cuts but you may have done that already. But if you got clean, white wood then you are off to a great start. Hang in there, almost all of us have had this happen so we feel your pain!

Also need to know, when to re-pot/ fresh soil, and when to start watering and how much now that she's been cut. I've never had to trim anything before!

You can up pot right now if you want while its still dormant. its old enough that any shock would be minimal if you were to just lightly root prune or loosen up the root ball while you move into a larger pot. Look for a wider pot versus tall.

You may want to seal the ends of the branches with Dap or Liquid Electrical Tape to keep them from rotting if they get wet.

Hang in there! I have one plumeria in the backyard, no idea what it is, that the tips do this on a regular basis.
Congrats on your beauty.

Love frangipanic!
Tally HO!