fangers

i'm not sure if i have some form of mild ocd but about three months ago i started having these thoughts that i had to fulfill. it's like if my mind thinks of an action - for example closing doors or doing something a certain number of times - then i have to do it otherwise i can't concentrate on anything else. i can never leave anything unfinished, for example schoolwork, even if i don't need to finish it. when i watch or read things i have to take in absolutely everything and if i feel like i've missed something even though i haven't i'll go back and check multiple times (for example, if i read a sentence but don't really take its meaning in i read it over and over.) i've also started washing my hands quite a lot always with soap, particularly before bed, and if i've touched anything potentially dirty then i feel the need to go back and wash again. my older brother was diagnosed with ocd when he was about my age (his was hygiene based; he washed his hands quite a lot as well) so i know what it looks like and what the signs are, but i'm still not sure if i actually have ocd. unfortunately my parents are not very educated about mental health (they actually made it harder for my brother to get treatment because they thought that their own 'alternative' methods would work, which they didn't - he did eventually get treatment in the end) and refuse to believe it's of any significance. i'd like to believe that if i went to them they'd be willing to allow me to go to a professional and be diagnosed but sadly it's not something i can be completely sure of. any advice would be greatly appreciated, thanks.