Betta Fish: I’m overwhelmed (multiple tank syndrome?)

I recently bought this 15 gallon off Facebook marketplace place just two weeks after getting my boy Saint. I absolutely love this hobby, I never thought i would get so cought up in it the way I did.

MULTIPLE TANK SYNDROME IS REAL. I found myself looking for a new and better tank for Saint the day I got him. Originally having a ten gallon vertical tank with tank mates, I moved him into a 5 gallon horizontal by himself, he loves it in there. However, trying to find him a tank I found a good ass deal for this 15 gallon with a filter. I finished putting it together a few days ago after having it for weeks, it is now being cycled due to the immense amount of research I did. I love how it turned out ! I think I did a great job but I’m looking at it this morning and I’m overwhelmed, I miss that space in my house filled with just plants but that’s not to say that seeing plants AND LIFE when I look at this part of my apartment is so cool. I just can’t help but feel like I made a mistake ? It’s only my 2nd tank ! And my last one until I graduate school HELP😭

Never the less this hobby is extremely therapeutic so long as I don’t think about the money, I guess I’m just wondering if anyone felt this way when they first got into this hobby ?