They haven't had vaginal sex. Telling him to wait isn't the best solution/advice in this case.

I would suggest her seeing a therapist/sex-therapist about the break-up to process with them. She is obviously traumatized by her first time which could suggest she was pressured her first time which could potential equate to rape. This is serious and you continually suggesting to have vaginal sex is not going to help the matter. If she's having panic attacks over it, the best thing YOU could do is support her in finding a therapist and not feeling ashamed she needs to process with someone about her experience.

You may also want to look into cultural differences to see if this is common behavior with other eastern Asians.

Also, you should be grateful she's putting out at all. Just because you're not having vaginal sex doesn't mean you can't have a meaningful sexual and intimate life. Having vaginal sex isn't the be-all-end-all to a relationship. You're still experiencing intimacy with your girlfriend and at least she trusts you enough to do everything else.