As one newbie to another, I'd like to add a little to this. First, I hope your extra pool instruction goes well and you are able to complete the OW dives as planned.
A lot of people have trouble with the mask clearing. You are doing something completely unnatural. Your face is immersed in water and you are still trying to breath. If you happen to get a little water in your airway, the problems multiply. The advice I got is to not do anything you are not comfortable with. For the mask removal, I flooded and waited until I knew I was in control of my breathing. Sometimes that was a couple of breaths, sometimes a half dozen. Do it when you're ready, there's no time limit.
The same thing goes for the OW. If you are completing the skills in the pool, you should be able to do them in open water. But if you don't feel right, then don't do it. You can call a dive at anytime for any reason, that includes your OW dives. I was having a lot of trouble on my first OW dive with a combination of overheating from the wet suit and restricted breathing from an ill fitting hood and wet suit. After getting into the water and cooled off, the instructor asked me if I was OK to go down. I said no, I didn't think I could dive with the difficulty breathing. We managed to make some adjustments and I was able to complete the dive with the class, but they also assured me if it wasn't right, we'd fit the dives in later.
Your instructor should be the same way. You've got several problems to overcome. It's likely you can overcome them but it may take more time. Take as much as you need to get it right.