Street level dealers often recieve tabs after they've travelled a long way in sometimes poor conditions , then they dont store it correctly. LSD is very sensitive for example to heat, impacts, and temperature fluctuations which all degrade the molecule. so this time you probably got a fresher batch or stronger tabs.
300 "true mics" of LSD is a really strong dose, you're almost guaranteed ego death. 150 "true mics" is plenty even for the most experienced trippers (as long as they took a long enough break between trips) . eating anything more than a few tabs at 150 could result in injury, even now you had doubts.
The good news is that what you describe is totally normal or at least sounds pretty much like what 200-250 true mics seems like , so you'll be alright, but it will take hours. i prefer committing to trips like that during the day because they can last so long (easily over 12hours).
hope this helps !