Welcome, Al. You are correct. Those squats are fairly high for the most part. You might need to take a few kilos off the bar and work on getting deeper. Your knees can go slightly further forward, which will help with balance. If I were coaching you, I would probably use a box to get you to the correct depth. Once you are there and convinced you can stay in balance, we would remove the box. I am also not convinced about the safeties on your rack. The don't stick out very far and are probably too low. If you could not stand up, I am unconvinced your safeties would be there to help you out.