OCD can bring down a person's self esteem in record time. You're exhausted from managing the thoughts and feel guilty for not having done ERP the way you should, or at all and even if you do the ERP you're still exhausted because it's incredibly hard work. I'm in the first group at the moment, knowing I should be concentrating on ERP and feeling guilty because I'm not, and exhausted because I struggle with the thoughts. I think being patient and kind to yourself is important and remember that OCD is tough and knows how to control and manipulate. Give yourself credit for keeping on going.