Just wanted to say welcome and glad you are here.
I'm also 25 and have had so so many blackouts. I could write a novel about why I hate them so much, but I feel like that is pretty much self-explanatory.
There were some sketchy nights while I was in blackout mode that I obsessively replayed over and over in my head even up to couple years later trying to figure out if something did or did not happen, etc. I cannot let that consume my mind anymore... it will drive me crazy.
I will never get those memories back. Whatever happened has happened, and even if I DID know what actually happened, there's nothing I can do to go back and change it. Worrying did NOTHING for me... just made it so much worse. Easier said than done, but I had to eventually just let it go.
Best of luck to you with the anxiety/panic attacks. I understand it a lot, but I'm also taking meds for them lol.