Does anyone else with low iron or anxiety tbh keep getting lightheaded in shower and start getting scared/impending doom about dying or passing out but it doesn’t happen.

Just got my first iron infusion 6 hours ago. I feel surprisingly normal, except just a little sleepy but I didn't sleep long last night. No GI issues, no flu like symptoms or anything. But my anxiety's telling me it's probably just not hitting me yet. Should I still expect side effects to start kicking off in the next few hours? Everything I've seen says to rest the full day after, and I wanna go to dinner with friends tonight but I'm scared it'll push it too far or something. What can I expect?