((((Amber)))) we'll do this together, I got the same news for Jazzy today. Others will be stopping by to visit, the acro moms are a wonderful group and they really take care of each other. There is a ton of information on the Acromegaly/IAA/Cushings support group on this site, but don't think for a minute that you have to leave Lantus Land. There are lots of acro moms in LL. Now you have two homes in FDMB instead of just one, your Lantus family and your High Dose family.
For right now we need to work on her insulin needs. You are aiming for blue, not green. It is also important to know that acros have functioning pancreases, so if you do find yourself needing to bring up a low number (it will happen someday, even though it doesn't seem like it right now), you'll probably need to go straight for high carb food instead of low carb like the other cats here. If that doesn't work, don't be afraid to grab the syrup. Acros' insulin needs can change suddenly, so if you wake up one morning and see a low number that is totally out of context, don't feel pressured to "shoot low to stay low" like we tell everyone else. It's ok to give a major chicken dose or even to skip doses sometimes.
The good news is that now you know WHY Meadow needs a higher dose than many other kitties. You know you're not doing anything wrong, you're just giving her what she needs. I hope that helps you feel a little less frustrated. I'm lucky, Jazzy's dose is not very high (at least not right now), so I can't relate to how you must feel shooting 13.5 units, but now you know for sure that it's the right thing to do.