Intimacy Struggles?

I don't wish to upset anyone with this post, I just really need some advice! When I was younger I experienced a lot of physical and sexual abuse and as a result was recently diagnosed with PTSD. It has taken me a very long time to trust anyone but I've finally found myself in a positive and healthy relationship. I'm very happy but I'm struggling a great deal with intimacy in our relationship. I have a very kind, supportive, and understanding partner but it saddens both of us that I am so scared of sex and intimacy. We tried the other night but I had a major panic attack and was a puddle of tears! I could really use some guidance as to how I can relax and be trusting. I welcome any and all ideas. Thank you! ❤️