AITA For Betraying My Best Friend

It's not as simple as it sounds, so hear me out. So I (43M) was on a long journey home with my closest friend, let's call him Udysseus (U for short) after a war and I noticed that our food stores were pretty much run dry. So I told U and he had us go to an island where he and another friend, we'll call him Golites (G for short), went off to find food. So they brought us to a cave and though I was skeptical of this island at first, the cave was full of sheep. Unfortunately the cave also belonged to a cyclops. He killed fourteen of our guys, including G, before we escaped.

So then things started going bad. We hit a nasty storm and U had the idea to anchor our ships to a floating island. But then he was going to go up and ask the god to help us. We didn't really have anything as an offering and gods are unpredictable anyways. So I told him that's a bad idea and his recklessness could get us all killed. But then he told me to stop questioning me. And I guess we needed morale at this point, so I complied. But later, after the storm cleared and we set sail, the crew kept pestering me. They thought U had gotten a bag of treasure from the god. I tried to resist, but the minute he fell asleep, I opened the bag and it let out that very storm! It blew us all the way across the Mediterranean and then most of our fleet was destroyed by a god.

After getting away from that, I wanted to fess up (see, I've got integrity!) about the bag, but he dismissed me and sent me with a scouting party to make sure this island was safe. And as soon as the men got comfortable, a sorceress turned them into pigs! I didn't go into her palace, so I escaped. But after that, I tried to tell U that we couldn't beat her and that we should just leave with what men we have. I was being pragmatic, but he went off anyway. Yeah, he came back with them, but I knew it was by an amazing stroke of luck.

After that, U changed. He became more ruthless. He ordered us to torture and kill a pack of sirens, which we didn't exactly have a problem with. But then we went to a dark water cave where I was finally able to tell U that I was the one who opened the wind bag. He told me to light up six torches. Then, from the water came a monster! I couldn't describe it, but it had six heads and it was horrifying. U just told the men to row for their lives and this monster at everyone holding a torch.

When we left that lair, I confronted him. He just left our crew for dead and ran! I was the only voice of reason for the crew and I had to take him down before he sacrificed us all. So I knocked him out and we found an island filled with cows. Once again, food was low. So I was going to kill a few to eat, but U told me not to because they belonged to Helios. At that point, I had accepted we were never going to get home. It had been twelve years and I was ready to give up. So I killed the cow and he got really mad and I got worried. Anyway, now he's being given an ultimatum for either him or us to be killed by the thunder god so I need answers quick please!