Don't give up. Reach out to your teachers and explain what you've written here. Say you want to go to uni but that you're struggling. Ask if they can help you develop a plan of action that will allow you to catch up. Also, modify your expectations. Whilst you may not achieve AAB, your year is still salvageable. The teachers will appreciate you being proactive and taking ownership of the situation. Also, by setting forth a plan to catch up, you'll hold yourself accountable and will be more likely to stick to the plan. Use COVID as a reason for the additional stress and not performing as well as you'd hope. Teachers will hopefully be compassionate, as this is a very unusual, once-in-a-lifetime pandemic.
I hope this helps. Good luck.
-Trained as a teacher