Abstinence is as easy to me as temperance would be difficult.

For some appetites, none is genuinely easier than a little. Moderation asks you to renegotiate the same decision every single time, and each negotiation costs something, while a flat rule costs one decision and then nothing. People who look disciplined are often just people who removed the question rather than winning it repeatedly. Knowing which appetites work that way for you is more useful than any general advice about willpower.

Take the one thing you keep promising to cut back on. Try a clean line instead of a careful one for a fortnight. If the clean line is easier, you have learned something about yourself, not about virtue.