Dear Erin:
“This entire situation is complicated beyond belief”- a big part of the complication will resolve if you can see that it is not that you failed (to love both people equally), but that it is not possible to love two people equally.
You can slice a cake to equal size portions, but you cannot slice your heart/ emotions into equal-size portions.
Your polyamorous experiment failed: it caused you fear, panic, guilt, regret and your head is spinning. Perhaps a mono-amorous aka monogamous relationship is a better choice for you (?)
anita