Having Panic Attacks Over My Dentist Appointments With Fillings and Wisdom Tooth Removal

I am 19 years old, living in Ontario. Back in April I went to the dentist for a routine checkup on my teeth, and during that checkup they noticed that I have a few cavities that would need filling.

One of the cavities is on my wisdom tooth on the right side of my mouth, and that wisdom tooth (at the time) hadn't fully breached the gum so it would need to be removed via surgery.

My dentist told me that they have scheduled an appointment for me to get fillings on my other teeth, and I'm going to have my fillings tomorrow, and both of the appointments I'm having full blown panic attacks over and I cannot stop overthinking.

The appointment I have tomorrow I'll be going on nitrous oxide which I am absolutely terrified of. I'm mostly scared and anxious because I have some personal things I have kept private from my mother who will be the one to take me and is paying for the appointment, who, if she found about these personal things, would be extremely bad for me while I come out all loopy, high and off my rocker while on the nitrous or coming down off it. I'm also extremely nervous about the nitrous itself. I know the nitrous is in a safe controlled environment, and that it's mixed with oxygen so that nothing goes wrong, but from what I've seen online I'm terrified that something might go wrong, because accidents can happen whenever and I inhale pure nitrous and ruin my brain, however I'm mostly scared of the potential of accidentally saying something to my dentist or revealing these things to my mother.

The appointment to have my wisdom tooth removed isn't scheduled yet, and it's the procedure I'm the most scared of because I'll have to go under anesthesia for, and I'm scared for this one even more so than the one tomorrow because anesthesia makes you even higher and loopier than nitrous does. So the idea I reveal these things while coming down off the anesthesia is making me lose sleep.

I haven't scheduled the appointment for my wisdom teeth yet, and unless I cancel the appointment tomorrow (which is unlikely since the nitrous has all ready been shipped, and my mother will have to pay for it) I'm going to vehemently tell my dentist that I refuse to do the wisdom tooth surgery.

I'm absolutely terrified of both of these procedures and don't know what to do.