What's a word for setting up a mechanism to prevent you from doing something in the future no matter what you may say or do then?

Solution 1:

I'd say you're talking about a Ulysses Pact:

a freely made decision that is designed and intended to bind oneself in the future. The term is used in medicine, especially in reference to advance directives (also known as living wills), where there is some controversy over whether a decision made by a person in one state of health should be considered binding upon that person when he or she is in a markedly different, usually worse, state of health.

The term refers to the pact that Ulysses (Greek name "Ὀδυσσεύς", Odysseus) made with his men as they approached the Sirens. Ulysses wanted to hear the Sirens' song although he knew that doing so would render him incapable of rational thought. He put wax in his men's ears so that they could not hear, and had them tie him to the mast so that he could not jump into the sea. He ordered them not to change course under any circumstances, and to keep their swords upon him and to attack him if he should break free of his bonds. Upon hearing the Sirens' song, Ulysses was driven temporarily insane and struggled with all of his might to break free so that he might join the Sirens, which would have meant his death. ( -- Wikipedia)

Solution 2:

A 'failsafe' or a 'fail-safe plan' might best describe the situation you outline. The word does not itself denote or connote a reflexive sense, which would have to be supplied by the context of use. Sense 3 of the denotation of the adjective, from American Heritage Dictionary of the English Language (fifth edition), applies most directly to what I understand of the meaning you desire:

fail-safe or fail·safe
adj.
1. Capable of compensating automatically and safely for a failure, as of a mechanism or power source.
2. Acting to discontinue a military attack on the occurrence of any of various predetermined conditions.
3. Guaranteed not to fail: "There is no fail-safe mechanism guaranteed either to contain or to restore presidential authority" (Arthur M. Schlesinger, Jr.).
n.
A fail-safe mechanism.

(American Heritage® Dictionary of the English Language, Fifth Edition. S.v. "failsafe." Retrieved April 26 2016 from http://www.thefreedictionary.com/failsafe )

'Fool-proof' might be another option, but because you're applying the term to yourself I have reservations about recommending it to you:

fool·proof adj.
1. Designed so as to be impervious to human incompetence, error, or misuse: a foolproof detonator; a foolproof safety lock.
2. Effective; infallible: a foolproof scheme.

(American Heritage® Dictionary of the English Language, Fifth Edition. S.v. "foolproof." Retrieved April 26 2016 from http://www.thefreedictionary.com/foolproof )

Similar, but even more pronounced reservations come with any recommendation of the parallel term 'idiot-proof'. 'Idiot-proof' is used more informally than either 'foolproof' or 'failsafe':

id·i·ot-proof adj. Slang
So easy to use or make that there is very little chance of failure: "idiot-proof recipes that cut corners by making use of packaged foods" (Howie Rumberg).

(American Heritage® Dictionary of the English Language, Fifth Edition. S.v. "idiot-proof." Retrieved April 26 2016 from http://www.thefreedictionary.com/idiot-proof )

Also note that, unlike 'failsafe', neither 'foolproof' nor 'idiot-proof' are used alone as nouns.

Solution 3:

The closest phrases I could think of for your scenario:

Your family members would be keeping / holding you accountable for your own studying.

You would be taking preventive measures to make sure you don't procrastinate.