I'd try dialing the dose back a bit and see if it helps. A racing or elevated heart rate is a really common side effect with the third compound, honestly the one I dislike most for the exact reason you're describing. You'll probably notice some elevation no matter what amount you're on, but if you climbed too fast to let your body catch up, maybe hold at a lower amount for several days and see if that eases things. If it doesn't feel any less anxiety-provoking, you'll know it's just part of the deal at any level and can go back to increasing. But if it does help, stay there a few weeks before moving up again. Personally, stuff like trouble sleeping or nausea I can just push through, but a racing heart paired with anxiety is what makes me stop and rethink things.