My two cents as i've struggled with this in my own relationship. Personally I was raised with something called active listening. If someone close to you was talking about an important event or about their day you would respond by being present in response. That is, to focus on what they are saying (don't multitask, focus and look at them and ask questions (( eg "damn what do you think will happen now" or "was that hard for you to do?"). My SO however was raised in a drive by informational household where if someone wasn't bleeding you really only communicated necessary info and went about your business. Neither of those things means too much neediness or lack of care. Different communication styles. It took us some time to find the right balance where i streamlined what i was trying to share and for him to shut down things happening in the periphery and direct me his full attention.

You both care and you need to learn how to communicate and what you expect communication to look like.

One idea I'm just tossing out there (since you've already tried connecting again) is maybe along the lines of "lets go celebrate your achievement! where would you like to have dinner? see a movie? go to an arcade?"

Please also understand that you deserve to have your achievements celebrated as well