I see a 60 minute bittering charge in your recipe that accounts for over half your IBUs. I merely suggest using a different, milder hop at 60 or dropping the amount of the Mosaic so that you're getting less IBUs and boosting the later additions to make up for it. Moasic can impart a very harsh edge to the bitter qualities but when it's used later, because it's a high-alpha hop, you get plenty of bitterness with a ton of flavor.
I might try something like 12 g at 60 minutes, 20g each at 20 and 10 minutes and 60 at flame-out, leaving the hop bag in for chilliing, assuming that it doesn't take too long, 15 or 20 minutes to get the temp lowered. That extended contact time acts as a whirlpool addition and will give you all the goods from the late addition.
