What you are asking about is called Harm Reduction. The act of reducing usage of a substance to what one feels is a manageable amount or with the intent of ending use completely.

It's my belief that harm reduction is the most difficult of all methods to cease or reduce the consumption of substances.

The Adderall is an ampetamine, I assume you aren't 'eating' it but snorting or another means of consuming...so yes the chest pains you are experiencing most likely are related to the use of this substance.

You say by afternoon you are 'shot' from so much smoking when it comes to the weed, consider this then, if you believe you are addicted to both substances, how would cutting back on smoking be of benefit to you? Addiction itself indicates a loss of control over an 'event'.

Best to consider your reasons for using in the first place. Adderall to control weight, weed makes you lazy and hungry.

Try an exercise program, the adrenaline produced by vigorous exercise mimics the effects of the adderall, and usually exercise results in weight loss or management. The lazy and hungry should be taken care of by the same program and end result is a healthier, happier you.