<human>: Got back with an ex for our 4 1/2 & final year together.  We were getting along great & enjoyed many of the same interests together, but he wasn't interested in working out past relationship issues so that we could build a stronger foundation in order to move forward toward marriage (as discussed before we got back together).

In fact, he wasn't interested in me at all.  No sex, didn't want to go out, played video games 20 hours a day, etc.  When I said I was moving back home (out of state) he put zero effort into keeping me or wanting to work it out, so I packed up & left, feeling completely unwanted.

The breakup was clean & civil, we told each other we loved each other several times, & afterwards we sent each other playful messages & I was under the impression we might even still have a chance.

A few days after the breakup I found out he was on a vacation with another girl, which is the same exact time he stopped talking to me.

I feel so betrayed, as if this was all planned.  To top it off, he never took me anywhere in almost 5 years together.  We took a 3 day same-state "vacation", but it feels awful that I wasn't good enough to travel with, but he's taking her here there & everywhere, & quickly.

There are no lack of offers to take me out, to put it mildly, but how do I start dating after being thrown away like garbage by someone who I thought I would spend my life with?

Can you condense the text into a few key points?
<bot>: Partner I would have worked through anything with didn't feel the same.  How do I open up again to someone without the fear of betrayal & indifference?