________ me coucher tard. I'm used to going to bed late. (HINT: use 'habitude') J'ai l'habitude de J'avais l'habitude de

You need the present tense because the entire sentence is in the present: you have the habit right now, as you speak. The English sentence is also in present tense ("I am used to" is present tense. "I was used to" would be past tense.)