It is not easy to give a boyfriend a breakup gift, but you should remember one thing, that is, your feelings for him when you broke up. If you still love him and want to reconcile with him, give him some meaningful gifts. If you are no longer in love with each other and just want to give each other a gift as a souvenir, then give him some gifts that are easier to keep.
You said you still love him and he still loves you, so you can order a pair of couple pendants online, with his photo printed inside and your photo printed inside his, so that you may be able to reconcile in the future.
Or you can give him a military badge, engrave what you want to say to him, or blessings, or words of nostalgia on it. In short, a beautiful relationship should be remembered, come on!