Communication feels complex when you have a lot of problematic thoughts going on in your head. So, my suggestion is to keep it simple. For instance, just say something along the lines of "i'm glad we both like to take our time getting to know each other" to your friend.

Regarding communication with your therapist, i hope you can realize that the more forthcoming you are about yourself, the more they will be able to understand and to help you. perhaps, if you are uncomfortable telling the therapist straight out that you suffer from HOCD, you could start by telling them that there are things you are afraid to tell them. that way, the therapist could first address the issue of fear and hopefully find a way to help you feel comfortable enough to open up. so, please let your therapist know that you feel uncomfortable telling them things and work on that issue. you appear to have a strong desire to get better; use that desire to let the therapist know you are uncomfortable opening up. all the best to you!