That could be it, Keith. I'd advise not to fertilize again until the leaves stop burning at the tips. Maybe miss one month, or give half the amount next time.
I found it online, and it's a liquid fert that you dilute at a tablespoon per gallon. Trouble is, growing a fruit tree indoors is really a lot different than growing a house plant. You can't just keep giving it the same thing all year round when you have it outdoors for half the year, then indoors.
