OP, congratulations on being selected. Can I persuade you to reframe this before it's too late? DH sounds pragmatic. He has seen the picture and doesn't want to make a trip to visit. I can see this might not be what you hoped for. However, you must celebrate this. Without him, I would suggest. Do you have friends/relative who would accompany you on a pilgrimage to see your painting in situ? Stay over night, go for dinner, have a nice breakfast in a hotel and then go and visit it the next morning. If my friend invited me to something like this I would be delighted.
I feel sure you have people in your life who can celebrate this with you. Seek them out, take lots of photos, enjoy yourself. Do not let this go unmarked.
My DH is not a massive patron of the arts and having attended a musical as a family once suggested next time he would wait in the foyer with a paper to save his ticket price.
I get living with pragmatic partners. However, if it was really important to me, he would have come. He likes a road trip and we have fun hanging out but I would have needed to tell him I his presence was required. Sometimes I spare him the arts, but occasionally, if DD is performing, I make him attend which he does with good humour. I indulge his interest in war in a similar fashion if I must although sometimes I suggest he might enjoy it more with another accomplice.
I think you need to be responsible for your own joy here though and find a way to celebrate with like minded folk who also love you. Don't let him shape the whole narrative. It's too much for one person to supply all the cheerleading in someone's life and while I think your DH could have done better, I think you need to enjoy this with others. Well done again, by the way.