Ultimately it's your body and your life. You're free to make your own choices about what you put into your body, and how you use it. Even if they are not wise choices.
Some things to bear in mind though:
You will not be 26 forever, and without change, you will not be 23 stone forever either, and you will get heavier and larger until the physical toll on your body catches up with you. Will you get to 30 years or 30 stone first...
A 26 year old should be able to walk, and do things like run for the bus, or go dancing. To not be able to do basic movements at 26 would be deeply worrying. Walking is a low bar to judge health by at such a young age.
It is easier to lose weight and get active when you are young. Past 35, 40, 45 it gets harder and harder and your metabolism slows down. Weight gains tend to accelerate with age as movement and muscle density decline.
Obesity affects health in pregnancy/ birth and often baby's health. Monitoring yours and baby's health gets harder the more excess fat tissue there is. Gestational diabetes is common and can lead to T2 diabetes. Babies can often end up straight in NICU to have their blood sugars stabilised. Extreme obesity reduces birth choices. If you have fertility difficulties, the first response will be for you to lose weight. That could waste precious time.
Assuming you become a mother, will you be able to easily play on the floor with an infant, rescue a toddler in a soft play frame, go on rides with them, run around a park with them?
Your 26 year old body is young and may be coping now, but it will get harder. How much are you willing to let your quality of life decline? Poor health is often invisible until it's too late.
You are free to ignore all opinions, especially unsolicited ones, but it is just biological reality that the more and more obese a person becomes, the more likely it is to impact their health and lifestyle and at an earlier age. Change can only come because you want it to and the long term benefits outweigh the difficulties.