The "peeling" you're experiencing is a sign that your adaptation plan was too ambitious - 0.3% three times a week is quite a lot for someone just starting out. Try alternating: one night with retinol, the next night without, and see if the irritation calms down; then, once your skin gets used to it, you can bump it up to twice a week. In the meantime, use a good moisturizer right after the retinol (wait a few minutes for the serum to dry first) and keep decent sunscreen on during the day - irritated skin is much more sensitive to the sun.
One thing that helps a lot is mixing the retinol with a moisturizer instead of using it on its own, or even applying it on alternate days with much less product. What's your skin type like - is it naturally sensitive, or did the retinol just make it that way?