Weight goal confusion

Hi Brooke!
My goal is to lose weight but I’m using my confusion about my weight goal to kind of doing it. I’m 1.65m (5ft5) and currently weigh 61kg (134 pounds). Doctors told me I am 4kgs overweight (so I should weigh 125 pounds) but I’ve always dreamt of being 50kg (110 pounds) or 55kg (121 pounds) because they sound like pretty numbers. So I’m confused, not knowing when to stop, being afraid that I could overachieve and be too skinny. The action I take when I’m afraid is to do the bare minimum instead of taking action. My fear of over-achievement is making me underachieve. So how can I get determined on a precise amount?
I mostly want to do it to stop my brain chatter around food and weightloss, though. Could my goal not be a weight goal?
Thank you!
Nan from Paris