I don't own Once Upon A Time In Wonderland and never will. No copyright infringement intended.
Will had a huge problem – he was in love with someone who would never love him back. Alice loved Cyrus way too much to ever think of him in that way and he was fine with that. Sort of. And he had fucked up Anastasia too much to ever get her back. Jumping through the portal had been a big mistake. And no matter how much he missed her, he couldn't play her games. She'd end up killing him sooner or later and that couldn't happen.
He just wished that helping Alice try to find Cyrus didn't hurt so much. They were going to be reunited eventually and end up living happily ever after. It was inevitable. But his feelings didn't matter – hers did. He was only on this journey for Alice. Will had been content in Storybrooke after the curse broke. He planned on going back after this was all over – it'd be for the best.
His heart had been broken numerous times since they started this journey, and Alice was unaware. He hoped it'd stay that way. He didn't need or want her pity. It's humiliating that he even feels like this in the first place. Will just wants to move on and fall in love with someone else – preferably someone who isn't evil or in love with another man. Should be easy, but it isn't, especially in Wonderland where everyone hates him. And Storybrooke has a shitload of couples so that's not helpful at all. But he has a feeling he'll be alone for the rest of his life. That is what he deserves after all.
It hurts every hour of the day that he's awake (and sometimes when he's sleeping), but Will can live with it. He has to - there's no other choice for him.