Help With Lavender Twist Redbud?

[LoneOrchid]

Last spring I purchased a 2 ft Lavender Twist Redbud as a memorial for my deceased dog (buried her cremains beneath it). After a brief stint of short-lived transplant shock, the tree did outstandingly well all through fall where it went dormant.

My concern is now that spring is upon us, the end (6 inches or so) of the only branch on this young tree is stiff and dry - accidentally snapped the last inch off in my hand while examining. The trunk is just starting to show tiny blossoms, but the branch itself is bare.

My yard is very heavy in clay. Not knowing how to go around this, I dug a hole over twice the size of the root ball and over 3 sizes deep, which I filled with mostly top soil but filtered through it some of my natural yard.

We've had massive rain pour this month, just now marking a new record for the area. I know this tree doesn't tolerate over-watering well, but thought the hole to be large enough to accommodate that.

I'm very inexperienced and am having a hard time finding enough information on this type of tree. Should I go ahead and prune the dead branch? And where should I prune it? Because the entire tree looks like one big branch sticking out of the ground - now over 4 ft high with an extra 2-3 ft of weeping overhang.