In my opinion, I would recommend taking your second 30mg dose right after a big meal (a proper lunch). That way, it will act as a continuous sustained release med, which is quite different than the bimodal release such as Adderall XR.
Either way, I would recommend cutting out ALL caffeine and cigarette usage at 60mg/day (e-cigs w/ nicotine is alright), as that is the FDA approved maximum for adults. The chest pain (angina) is quite serious, and is your cardiovascular system's way of telling you that you are taking too much Adderall at once. I can't condone using Adderall after having chest pains, but if you must take them, take 15mg sublingually and 15mg orally after a wholesome, proper breakfast, then take the other 30mg orally after a wholesome lunch.