Advice needed

Hi everyone, I am considering narrowing down to just one language to study. Although I've ALWAYS dreamt of being a polyglot I'm not sure it's for me anymore. I am native English, and I grew up speaking Italian so I have B1ish fluency, I've taken Japanese classes in the past at my university so I'm A2, and i taught myself some serbo Croatian in middle school but never got past A1. I've recently started learning Thai and I'm now super connected w the culture because my girlfriend literally lives in Thailand (we go to university together in the US). I'm super beginner with Thai but I have a native speaker to help me so I feel it's worth investing time in. I would love to keep learning Italian to become B2/C1 at some point. Japanese and Serbo Croatian are not as important to me but I'd hate to lose what ive gained. Does anyone have some suggestions as to what I can do in my situation? I'm not willing to give up my Italian knowledge, but I also want to gain more fluency in Thai. Any advice is appreciated!!!