I know how "set" some of us can be on a specific number "goal" or "I am going to lose 50 pounds in X months."
May I suggest that instead of looking at a number that seem impossible - and having a constant reminder of what you HAVE NOT done... that instead, pick a really logical goal or EVEN (horrors) a goal that WE KNOW we can attain.
I was inspired by an acquaintance on facebook who said he goal for that year was to lose 20 pounds. I thought about it, for a couple months......and decided that I was tired of my weight gain and MY goal could be to stop gaining weight, and maybe lose 10 pounds in a year. Reversing habits that had snuck back over 8 years.... and heck....it started working. And instead of setting myself up for failure... I was; to myself; an amazing success !!! Maybe I COULD lose 20 in a year ! I had lost that and more by 7 months.
I also knew what weight I COULD NOT maintain back when and how miserable I was trying to continually FIGHT and never win. So I set MY GOAL for 5 pounds over where I had managed to maintain for several years.
NO, I won't be a size small or even a medium. But I started at 5'3 (now 5'2) and 320 pounds at age 53. I have lost 147 pounds. I am good with that.
This may not apply to you. This may not be you. It is me. I managed to do this as a full time working 64 year old human with some auto immune disease - exercise is not something I can do much of. I practice meditational yoga, actively garden a few times a week. I take care of a small flock of a couple dozen chickens, so I rake and hoe and haul things around. I have a teenager who comes and hauls 40 pound bags for me on the weekends. But I am active even in times of Covid, grow some of my own vegetables and fruit and salad greens .... life is good. Find your Good.