Sexual Abuse Support Group
Sexual abuse is a relative cultural term used to describe sexual relations and behavior between two or more parties which are considered criminally and/or morally offensive. Different types of sexual abuse involve: Non-consensual, forced physical sexual behavior such as rape, incest or sexual assault, or psychological forms of abuse, such as verbal sexual behavior or...

Shame is also a very common feeling and it is possible to heal to the point where you no longer feel ashamed. Shame only has power when you don't talk about the event that caused you to feel it. Talking to a therapist (or maybe you have a great friend who will listen compassionately) about what happened will remove the shame you feel.
You can heal from what happened and you can go on to have a wonderful relationship with your boyfriend/husband - without being triggered all the time. Hopefully you are working with someone but if you are not I hope you will consider it because you do deserve to heal.
Take care
The emotional impact was and still can be devastating. I have broken down in tears after because of the shame and guilt I feel, though I have not done anything to feel that way.
I wish I could tell you it gets better, but I have yet to have that happen. Like you said sometimes it is fine, but then it hits me like a freight train out of control.
I wish you all the best and hope that you can find peace despite this.