My dear. Stories like yours are what sicken me the most about our situation. We are denied a fundamentally basic human right to mourn properly. I'm sorry for your loss and I hope you find a proper way to celebrate your fathers life.

As for the relationship. Yeah, it sucks and its going to take time for you to feel better about it. You just have to let time do its thing. And speaking of time, you finding out now before making any commitments with him has saved you a lot of time. If he was doing this now, you'd bet he'd still be fucking around if you two were married. In this situation, you would inevitably found out but perhaps much later and where other more complicated factors could be in play.

The travel thing. Sure going to Thailand would be awesome. Let me ask ya something because I don't think you're much of a traveler. I could be wrong. Have you been to Hawaii? Alaska? Puerto Rico? If you have not visited any of these, you're missing out on an opportunity to get a 'foreign' feel, whilst being in the USA. Trust me, I and many dreamers here, have been to those places and it's an experience that you are not likely to find exactly anywhere else in the US.

It's going to suck before it gets better, but you will be ok. Good luck.