Having worked in a residential setting with 16-25 year olds I would say this is completely normal! My ds 13 is exactly the same!
the first thing that strikes me in your post is that you say you are ocd in the rest of the house. Is it possible to want your 13 yr old to maintain your perfect standards? Cos you are going to have to accept that a 13 year olds priority is never to keep their room as if it was in a show house!
Having dealt with lots of young people and messy rooms, there are lots who were never taught to tidy and clean for whatever reason - some cos their parents didn't care and some cos their parents did it all for them.
Set some basic ground rules - like a) dirty washing goes in a laundry bin that is in their room b) basic levels of hygiene are adhered too c) pocket money not given unless room is tidy (don't set a tidiness level that is the same as the rest of the house) d) you help them do it if necessary one day a week.
My ds is terribly untidy, as am I naturally and I really have to work hard to keep the house in reasonable order. My mother was very ocd when I was younger and would do most of it for me as she wouldn't leave it, so every morning she would tidy my room whilst I was at school etc. This did not help me one bit!
For my ds, I have basic rules, but I also go in and "help" him tidy his room. I don't really help him though, I sit on his bed and chat away to him, offering suggestions about where to put things and what he still needs to do. Not in a condescending way at all, it's just when faced with the mess and being told to tidy it he just doesn't know what to do. You have to teach them! And unfortunately it's a slow process.
Sometimes if he is being particularly bad, and it is affecting the rest of the house I do threaten him with black bagging everything and putting it in the bin but that tends to be a last resort and a threat that is used very rarely!!! (An I have never have had to carry it out!) On the whole though I try to avoid confrontation, as it doesn't help.
As he has got better keeping his room tidy I have gradually put in more "demands". For example he used to just have to put dirty clothes in the laundry basket in his room and I would do collect it as and when, now he needs to bring it down when it's full and only then do I do his washing.
Now my house is not a show house, but it's clean, never dirty. Bathrooms and kitchen always clean and downstairs hoovered every other day at the least. It's very rarely tidy, but I think cleanliness beats tidiness in the importance stakes any day!
Pick you battles with your teenagers they like to rebel so start with something manageable and achievable first and then add to it. So think SMART - Specific, Measurable, Achievable, Realistic, Timed. So telling them "this week you have to keep you room tidy and clean and I don't want to see any mess in there" would not work. But maybe saying "on Tuesday I would like to hoover your room, so please clear the floor so I can do this. Then on Saturday I am doing a sheet wash so please strip your bed when you get up and bring it downstairs" is much more likely to have an affect.