Realizing how big I’ve gotten

Ever since covid I gained weight, I had the opportunity to work from home and during this I would snack on so much. I would sleep late and not watch my health. I started noticing my clothes didn’t fit little by little and this whole time I thought I gained 20 pounds max, I didn’t. I started getting stretch marks, which luckily don’t bother me. My boobs grew. I gained 40 pounds. I feel horrible that I let myself get to this and it was mostly because I didn’t have to get ready to go out so I never really watched myself change. I weigh 160 right now and it was just a shock when I finally stepped on the scale to see that number. I’m short so I was told I should weigh around 100-115 when went for my yearly physical. For the past few days I’ve been doing 5 miles a day of cycling but will add more exercises to my routine. Is anyone recently starting on their journey to fitness? If you have thyroid problems (like me) was it more difficult to lose weight? Or is anyone almost at their goal?

My goal is to get to 125 pounds, almost close to before but 115 if I can.

*tips would be appreciated