Milan had better focus on their Serie A matches more than ever from now on. Because they got a really disadvantageous result against Inter in the Champions League. Hence it doesn't look like they have a good chance to move on to the final round. Because of this they can at least focus on the Serie A now to carry themselves into top four. Besides even if they eliminate Inter somehow it is still too difficult for Milan to beat one of Real Madrid - Manchester City duo.
Hence I see only one way for Milan to join the Champions League next season - finishing the Serie A season in top four. Milan seem to have easier fixtures than Inter in general. The only tough challenge looks like it is against Juventus away. I think Milan can leave Inter behind if they play dedicatedly.
Yes, I agree with you, Ac Milan should focus on Serie A to enter the UCL zone next season. Because Finishing the season in the top four in Serie A is definitely becoming realistic for Milan at the moment.
However, in my opinion, even so, Ac Milan still has to try their best for the UCL this season, and AC Milan in leg 2 just needs mental recovery. Confident in the abilities you have. If you play calmly and without the burden, AC Milan will play more freely in the second leg.
The mission in leg 2 is to play carefree. no need to chase the target of qualifying for the final, let's just say it's over. You have to be ready to accept reality, the achievements until the semifinals have been very good with the squad you currently have. Doing so can make players play without a burden. But still playing all out has been all out since kick off. Trying to maximize it so that it creates goals faster against Inter. Then the score was 2-1, continued to increase the tempo until it was 2-2. Just hoping for a miracle comeback.