I pruned my Crepe Myrtle late fall last year and it has not come out of dormancy yet. Did I kill it?
Winter was so hard last year, and you're at the northern limit of crepe myrtle hardiness, so it's likely that the winter weather is to blame. Of course, this is one reason why pruning is recommended for early spring. This article may give you more insight, in case your tree is still alive:https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/best-crepe-myrtle-pruning-time-when-to-prune-crepe-myrtle.htm
This article may help you determine if your tree can be saved: