I get you 100%!
There's no point hearing that there's "much better" bands out there, Dream Theater is the masters of that type of sound. I am not saying there could be something better out there for you, just that if this is the type of sound you like it can be impossible finding something better.
I found love for DT by going from power metal, a genre that many times had prog elements and strong melodic metal songs. DT was the perfect evolution from that and it wasn't because prog was the ultimate genre for me, it was just that DT took element that I love about prog and incorporate them songs varying from epic, emotional, popish etc. It's colorful and comes in all kinds of different well crafted variations
Going into DT and loving those elements I naturally thought prog in any shape would be a great match for me. I have browsed through tons of prog bands on progarchives.com as well as recommendations and I like maybe 0.01% of the prog out there. Usually bands like POS, Riverside, Shadow Gallery, Circus Maximus, BTBAM or similar that share elements with DT within prog metal genre. However most other bands is more restricted to certain songs or albums.
In the end I am fine having a band I can't find any replacement for. They have tons of good songs that I never stop caring for. I don't think I will find a better fit in my life. Still there's tons of other bands with great music to listen to!
Some song recommendations as you maybe have a similar taste as me:
Circus Maximus - Architect of Fortune
Circus Maximus - Last Goodbye
Riverside - Egoist Hedonist
Pain of Salvation - Idioglossia
Shadow Gallery - The Archer of Ben Salem
Haken - Puzzle Box
Between The Buried and Me - Lay Your Ghosts to Rest