Yikes! My sympathies Pat as it sounds like you have gone to great lengths and the Bermuda grass keeps winning the battle. You can go online to Amazon and try one of the liquid Bermuda grass sprays that should spare your other plants but I do not have personal experience with these herbicides so be sure to follow instructions carefully. A different approach would be to put your plants into containers and let the area turn into a Bermuda grass lawn with pots of plants sitting on top. The truth is that seeds of Bermuda grass can float in the air so even if you get rid of every root the weed can return and you must be vigilant about digging out every bit of this weed.  Have you thought about moving? Keep growing, (but not Bermuda grass) Marianne Binetti