Overcoming Trauma and Building Relationship Trust

Hello. I'm brand new here and giving this app a whirl. I have been diagnosed with both ADHD-Combo Type and complex-PTSD. I began a new relationship with someone last August 2021 after being in a 12-year intense Narcissistic relationship that ended with me feeling "feral", the best word I can describe it. My current relationship is so much more wholesome than I honestly ever have been; however, it has also made me realize how much emotional baggage, wounds, and trauma my past relationships have done to me, specifically my most recent 12-year one. I have found I have such a lack of trust in just about anything. Past trauma, I have found, has done quite a lot of damage to me with trust and in feeling extremely insecure. I am fighting so very hard not to allow this damage to effect my present relationship. My medication alone does not seem to be helping. What alternative treatments has anyone used that has helped them significantly in similar situations?