First dose, 300mg

So i took my first dose of 300mg. It took about an hour for the effects to kick in. I didn't experience any hallucinations other than a few black dots on the ceiling if I moved my eyes really fast.

I felt very tired, heavy and lightheaded. Sometimes I would forget to breathe which caused a sudden heart palpitation. I thought it was a heart attack so it kinda startled me.

Should i try upping the dose next time? maybe 450mg ?