"Whiteboard" and screen recording apps I work as a teacher (I teach math) and in this situation where schools are closed and are offering distance learning I need to record lectures and share them with my students. Since I need to show how to solve exercises I need some app to use as a whiteboard and an app to record the screen.

I have a MacBook Air (2019) and a Wacom by One tablet, and at the moment I'm using Microsoft OneNote for Mac as a whiteboard and Screenshot (QuickTime) for screen capture.
The problem is that this combo is unbearably slow and laggy: it happens that I have to interrupt the recording every couple of minutes because of that, and sometimes the I lose control of the tablet (it start connecting any point I touch with a straight line).

I find the two apps I'm using excellent: OneNote has all I need, and with Screenshot/Quicktime handling the videos is immediate and straightforward, but working in this way is a real pain.

Do you know how can I fix these issues? Or do you have any suggestions for alternative apps?

Update: I also tried ApowerREC for Mac as an alternative to QuickTime, but perhaps it's even worse.

Here's a gif to show just how sluggish it gets after less than 1 min of recording:


Thanks
Keynote on your mac is maybe a good way to make a lesson. You can make slides of your lecture and record your voice lectures with it. You can then record the whole slide show as you go through it. It has a great LaTex equation maker with all the symbols you'll need.

I hope this is what you are looking for.