At the outset, did you mention to your treating doctor about your Vertigo?
Usually if that has been mentioned, on the side of caution, I for one would have kept the Isotretinoin in abeyance; first sorted your vertigo symptoms and then, restarted isotretinoin when things were under control
Do check with your treating Dermatologist and go with her suggestion
Godspeed 🙏
Next Steps
Revisit your Treating Dermatologist and confer with her
Health Tips
Fluid intake and good rehydration will be useful
Avoid driving or handling sensitive machinery/equipment etc while suffering from vertigo