12 kg is not much but if you haven't been able to shift them for so long and you have even considered drastic measures such as surgery, then it is enough for you.
We can't know how this weight makes you feel. Give it a go, maybe don't buy too many to see how you respond to it. Some experience severe side effects, some none.
While you wait for the tests and stuff, would you try to eat differently?
Having only one animal protein meal a day instead of three? try to swap the yoghurt and eggs for fibre , so flaxseeds or chia seeds with fruit for breakfast (chia seed pudding with frozen raspberries minus the honey/syrup is really nice) , a big salad or soup for lunch with at least 5 different veggies (green beans+ tomatoes+cucumber+red onion+ parsley) and maybe a couple of spoons of lentils/chickpeas/beans and make it BIG, and then your dinner with your meat/fish/eggs/dairy-product/
People don't realise how inflammatory animal products are until they change to more plants. Increase the variety of your vegetables. Don;t worry about missing on protein. Every single food has amino acids, so they will sum up by the end of the day.
If you focus on having as many as possible and not focus on what you cut out, you might be surprised. From asparagus to zucchini, really from A-Z.
Often, it is making something different that brings results and you are in for good taste. A French ratatouille (easy on the oil), oven roasted pumpkin, a rocket salad with pear and walnuts (just 4 crumbled) , sautéed okras.
In those who can't absolutely lose weight no matter what , it has been found that their gut microbiome was the reason. By tripling or more the vegetables you eat, possibly including some fermented food such as real sauerkraut or nato/kimchi , you will make changes in your gut.
Whatever you do, I hope you are successful.