Q.Leaves on my weeping cherry tree not coming out
My weeping cherry tree bloomed beautifully in early spring, but now only one branch has a few leaves. The other branches appear to have the leaf buds browned. Could have this been caused by 3 different frosts after it bloomed? The most recent frost was last week. If the frost hurt the leaf buds, will my tree come back or is it dead? What can I do to help it come back?

Yes, those late spring frost most likely effected the blossoming and flowering of you tree.
Just have patience and wait and see. Your tree will most likely recover.
Here is a link to refresh you with the care and pruning requirements of the Weeping Cherry.
https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/weeping-cherry-growing-tips.htm