You are being so hard on yourself for missing the bus. It's hard getting around via public transport. I wonder if calling to cancel due to the bus issue is the same as a 'no show'. To me, a no show is just not showing up and not notifying your T that you are cancelling. Maybe you could ask about that and even ask that your 'no show' be reset to zero. Policies are sometimes more flexible than we think

That's nice that T's schedule allowed you to be able to get another appointment so soon.