You need more perlite in the soil when you re-pot.
Looks like a pH problem and possibly lack of calcium.
Lose the rainwater and switch to tap. This may sound strange, but tap water is actually preferable. Rain coming off your roof has a number of issues- no calcium or magnesium, which are found in tap water and the plant needs. Acid rain- nitric and sulfuric acid- no good. No calcium carbonate means less capacity to buffer pH. Tap water is better.

Foliar feed right away with a very dilute solution of your miracle grow fertilizer to stop the deficiency from getting worse. Flush with tap water, poke EXTRA holes, and allow to dry pretty well before next feeding. One of the problems looks like overwatering actually.