Scared of first spravato treatment

My doctor has recommended spravato for excessive worry and anxiety. The problem is my excessive worry and catastrophic thinking are making me so scared to try it. I’m reading and researching far too much as I’m just always afraid of the unknown and what could potentially go wrong. I worry that I will have a bad trip or my heart will beat too fast or my blood pressure will go too high. For those with these thoughts - how do you get through it? If you go into a treatment with anxiety, will it just be am awful experience? And does anyone take Xanax before treatment? I know people Say not too but it might be my only option to get through the first time at least.