His trauma still equates orgasm with failure. A majority of people experience erotic difficulties due to negative body memories. The trick is to persevere in finding a solution. Don't fake orgasms. You are lying to yourself and your beloved.
True intimacy begins with honesty.
Let your lover get over the ego blow and get on with finding solutions together. Do talk or write about the feelings that come up for you when you experience sexual trauma. This can cut vague but overwhelming fears down to size. Journal or letter writing or speaking with your lover or a safe friend can be very calming. Sexual trauma often comes up during the sexual act.