I lost over 100k troops in Valiant and did not get them back when event ended?

This is not true about Valiant. During Valiant, any troops killed go to the State Infirmary, and then are returned to you fully healed after the event ends. Sometimes you have to wait a short amount of time before they are returned, but they should show back up. Wasteland is the State vs State event where your troops are wounded/killed as usual and not sent to the state infirmary.

To the original question, if your troops were truly lost during VC, you will need to contact Customer Support, there isn't anything anyone on this site can do for you. I would suggest looking in your Alliance Infirmary though, it is possible you had wounded end up there prior to VC and you didn't notice until after VC.

Troops don't get healed automatically in Valiant Conquest. They can be killed or if you have more wounded than can fit in your infirmary then they can end up in the Alliance Infirmary. View that building to see if you have troops there to heal.