I feel you alot Anon and sorry you're experiencing this I'm hoping i can help you with your predicament. Having episodes of guilt/shame is really common for OCD sufferers. We makes mistakes: say or do "bad" things (which we think are bad, but could really be nothing much) and after the point if realising it and feeling that initial pain, we then begin the obsessive thinking, the guilt starts, and it takes on a life of its own. Most people cut it off after realising it, feeling something initially and learning from it. We continue from after that point, punishing ourselves, and it becomes unproductive and not useful to use to feel excessive guilt and shame.
1) You need to realise something key. If you felt that the things you did in your past were 'out of character'... What is your character? Someone that must live life 100% to the rule book? Someone who ruffles no feathers in life, saying no bad words, living so perfectly.. Theres not a person on earth like this.
2) You need to slowly break down what you expect of your character. You will say or do some bad things in life. Its guaranteed. Its part of being human and i promise you everyone makes mistakes. With certain dynamics and situations and mixing with different people - we slip up and say things, we do things without thinking.
3) But an even more important thing. Even if you conscious do something to cause someone harm, and then realise and seek forgiveness and feel regret. That shows how good for a person you are. You can forgive yourself.
I promise you what you did or said in the past, people wouldn't even remember or if they did they would say to you not to worry, and your conscience should be clear.
If you go about this life trying to be perfect, you walk around with such tension. Your mind will find something you're doing wrong and catch you out. You need to accept being human means i will do good things often, and I'll occasionally do or say bad things. Its part of it and i won't fit myself into such a rigid view of myself.
When humans get unhappy, most people will be snappy, we will be rude, we might say ridiculous jokes when with friends to laugh, jokes that we may regret.
I know all this because i lived through it, and spoken countless hours in therapy over it. Finally im curbing it for real, and accepting a future where i won't be perfect. Its not a realistic life you want to live. I'm not saying to try do bad things, always seeking to be of a good quality which is only real when we are giving, its just not falling to pieces when we do make mistakes, its part of being human.