YankeeJim:I think you're selling yourself short. The jump to Legend pushed you to the back tees with faster greens and basically turned your driver/wedge game into a more normal diver/long iron game. Those longer irons aren't going to stick as well as the shorter ones so learn your 3 4 and 5 irons and play strategically, you'll be doing fine in no time. :-)
+!
The difference in tees between TM and Legend are significant, and it does take time adjusting.
My advice to TM close to tiering up is to use a 3W from the tee - this simulates the extra distance you will be playing the approaches from. The other is to avoid red tee tournaments (not applicable in the OP''s instance).
Personally, this is when the game became a challenge again (after using starters till I made Master) and is the way the game should be.
Other advice to the OP is rejoin/join a good CC - one where the members can offer advice and help you become a better player.
Do not worry about your average, that will settle down in time, just have fun and enjoy the journey.