A second-place finish is rather impressive and surely a great achievement. I am looking forward to seeing what the future holds for your team. It looks like you're steadily improving, and I'd be optimistic if I were you.
Tactically - Do you plan on changing the tactic to a more relationist approach? Or the issue was the lack of a 'cutting-edge' player to give you the edge over Dortmund?
I recently started a new save, building Esteban Granero's Marbella from the ground up, with a focus on youth development but without it being youth-only, so I'm taking a lot from this thread regarding scouting and development, it's been a huge help - So thank you for that! I plan to eventually post that one here on the forums but I'm going to see that I actually enjoy the save first. Groningen was too enjoyable and before I knew it, I was 3 seasons in with no way of actually summing up the progress I made.
BTW - A great squad view there! I might do a similar one myself.