Here is some advice if you are young and have not had OCPD for a very long time, like me. Because of the long length of time I've had this, and the fact that it went undiagnosed until my self-diagnosis just a couple of years ago, it has been able to grow and mature.
The nature of this condition is that is can worsen over the course of time. It has proved to be so with me. It has worsened, become more entrenched, overwhelming and all-encompassing.
My advice to all younger people who have OCPD/APD, is to do all they can to improve their condition whilst it's still in its early days - before it can grow, mature and get a fixed hold on you.
Take advantage of knowing what your signs and symptoms are. If you must do things in a particular, perfect order, then deliberately start to do things in random, imperfect order - even if it annoys you at first.
If you hoard, then deliberately start to throw things out - even if it's painful at first.
If you try to impose your perfect ways onto other people, then deliberately make yourself give these poor people a break and allow them to do it their way - you might learn something useful if you let other people do their own thing.
Instead of keeping yourself to yourself and not opening up to people, deliberately make yourself open up and talk to people about yourself. It might be hard at first, but it'll become easier in time - and it might turn out to be quite pleasant.
Etc, etc, etc. Try to oppose the traits and weird ways that you know are OCPD/APD ways. Otherwise the OCPD/APD will be allowed to grow and get bigger and take you over, so that you become a prisoner to it.
So fight it and oppose it, or ease up on it a bit!
I also firmly believe that it is highly important to try to do relaxation techniques and exercise to relieve stress. In my opinion, as someone who is "very experienced" in OCPD/APD, this condition can worsen and become more of a problem because of stress. Conversely, I think OCPD/APD could have less of an impact on one's life if stress could be reduced or alleviated.