YES, these are the exact symptoms my son exhibited and still struggles with(also, OCD often co-morbid with ADD). My son 15 and was diagnosed ADD inattentive earlier this year. He's on Adderall (stimulant). Went from Ds & Fs to As in summer school, back to alphabet soup this first quarter high school. So maybe needs up in meds or diff meds. I plan on going to a specialist soon vs. GP and social worker. They just don't know enough about this condition specifically.
Definitely look into it. Inconsistent effort and self-sabotage (not handing in homework tho done) are classic symptoms.
Google your local CHADD site and they should have page with local specialists.