I understand. At the time of rest, the conscious mind is not in control. The old negative thoughts get the chance to come back. You can listen to the affirmations at least 3 times before taking rest. The last one while lying on bed, just before sleeping. Hope you are also writing the affirmations. The writing therapy is a powerful method of getting rid of negative thoughts in the subconscious mind.
Do not worry. keep patience. W e do not want quick solutions that come in the influence of medicines, but healthy solutions that will change the negative patterns permanently.
I am happy that you reached out to me. do keep in touch. I am with you in this journey to get well.
Wish you all the best.