Hi Kathleen,
I went ahead and checked the data you have collected in regards to your Angels' Trumpet and see that it is east facing and in a partial shade location in the Concord area of California. Angels' Trumpet is really only hardy in zones 11 and higher, although I've seen it do pretty well in zone 10 coastal regions of California. It is probably stressed from being in a hotter location that can be prone to some frost in the winter and is failing to thrive and bloom. Has it bloomed by itself since you have had it in its current location? Best regards~ Ian