Try not to freak out about going (easier said than, yeah yeah). Not just my personal experience, but I've read so very, very many times on here others that feel that way, but make themselves go anyway and
end up being very glad they went.
Avoidance feeds fear. And we can get swept up in imaginary scenarios of all kinds of dread things. But they're not real.
They say the vast majority of anxiety is future and past based thought. Which is the whole thing behind mindfulness. The future's a projection of our minds, the past is water under the bridge. The more time we fret on either is energy basically wasted. The only moment that is real is the present.
Breathe and focus whatever amount you can (even if it's only a little) on
right now. That's the place to be. If you wander out, just bring it back in. No limits. It's there all the time, ready for you.
If this feels impossible right now, that's ok. Sometimes even just remembering the concept can help.
Sending good calm thoughts your way.