I need help with my save

I'm doing a Hertha BSC save with two goals: 1. Bring balance to the German Bundesliga by stepping over top teams (Bayer 04 Leverkusen, Borussia Dortmund, and 1. FC Schalke) and eventually dethroning Bayern Munchen 2. Bring glory to the club that represents the capital of Deutschland
So my first season I ended at 6th place, which I thought was a very good result. I made a few signings that had a lot of success. In addition, I had a lot of youth players pushed into my "camp" (I guess), so they seem to have potential. Making EURO this year was exciting.
In my second season, I was knocked out of the EURO cup in the quarter final. I wasn't expecting to win, so I thought it was good enough. What excited me the most was that I was able to come in 3rd place in the league. This was far beyond my expectations as a weaker club. This gave my a lot of confidence for my next season.
My third season started and I was on top of the world. I made key signings to help with the long road ahead (that seemed to get shorter). I was then killed in the Champions Cup, failing to even qualify out of my group. The season was going like a roller coaster for me. I could beat teams in the top half fairly easily but then teams near the bottom would take me out. I also could never beat Borussia Dortmund or Bayern Munchen. I never expected to, really, but it seems that my players would have a run of form for harder teams, just to be stopped by teams that I should've taken care of easily.
SO I guess my main concern is how to be consistent. My tactic is fine, my players seem to be fine, and I am taking care of training. What can I do now?
Also I am concerned with how many youth players I have. How can I tell which ones to keep? I am still new to this game so there may be some things I am missing.
Thank you to anybody who helps!

Would be helpful if you posted a few screenshots to go with this... Not easy to say who you should keep and who should get booted. Also, post a screenshot of your tactics and instructions