world i wish i had been able to advise you about disclosure before you took the plunge. my DH had a similar reaction to your DP, though it actually took much much longer for him to come to terms with the whole thing. i would say years rather than days.
thing is, even if your DP did think badly of you momentarily after you told him, IMO men deserve just as much sympathy for the bullshit they've been fed by society re: rape. both sexes have been propagangized when it comes to sexual violence. both sexes believe and perpetuate rape myths. both sexes sometimes need re-educating.
when a man (even a non-violent man) comes face to face with a woman who smashes his illusions about rape etc., all those comforting lies (consent is implied, some women ask for it, blah blah blah) fall away and it is a MASSIVE shock.
the lies (even if they are things he would never admit to believing) are comforting because they create an illusion that a man's loved ones are safe from rape because they're "not like that". now he has to deal with the cold hard reality that ANY woman, even a woman who he loves and wants to protect, is a potential victim. and there's NOTHING he can do about that, besides not rape women (which he was probably not planning on doing in any case!).
my DH has said to me "before i met you it had never occurred to me that "normal" girls could have suffered like that" (bear in mind he was barely in his 20s when we met, with v sheltered religious upbringing in v conservative country). telling him what happened to me i think literally killed something inside him. he didn't want it to be true, he didn't want to have to accept the injustice and the helplessness. it took him such a long time to come to terms with this horrible reality.
now almost 10 years on, he still apologises to me every now and again about how he responded at first. he's now fully educated on sexual violence issues and will be the first one to call out his peers for misogyny and so on. it's just that he had never had to face that stuff before. it was outside his frame of reference and it totally panicked him.
(he's now the most supportive person in my life by far. but then, he's not a 20-year-old anymore. he's had time to get educated and moderate his own emotions about the whole thing.)
people are not perfect. disclosure is really a loaded thing to do. i always advise people to lay the groundwork first, and to prepare themselves for a very upsetting reaction, because you can't ever tell what shock will do to a person.
i just wanted you to know i understand your feelings as well as your DP's. i wish you both the best.