Disappointless

I thought it my be time to revive my neologism for when one feels particularly disappointed after trying really hard, being really thoughtful and considerate, and all for naught.  For example, "I can't believe that guy shot down our proposal in a faculty meeting, especially after we all worked so hard to make a balanced document!  That was totally disappointless."  Or: "Wow, we started off with that compromise of 300 billion in tax cuts that actually don't do that much for most Americans just to appease those people and those very people still went around whining like babies and making disengenuous arguments.  That was truly disappointless."