weigela's are deciduous, i think, so i don't think you have killed it by pruning! i think the correct time to prune is after flowering-i guess how much you take off depends on your available space. i hoiked an inherited one out of the garden when we moved here, i found it awkward to prune as it had quite an arching habit.
hopefully by now you may see some tiny buds on the stems?............
i am open to correction, but if you pruned last year you may have lost some of the flowers for this year. hope this helps........
over to (hopefully) an expert............. :)