The evidence for Bitter Gourd is weak to say the least and Metformin is much better at doing the same thing. Being medication-free isn't anything special or clever, Many people on here with low HbA1c scores take Metformin as well as eating in a LCHF way. It might not do the whole job, but it definitely lowers your BG and it's safe with a few well-known inconvenient side effects which tend to fade over time or use of the Slow Release versions for most people. Unless you have a particular bad reaction to it, and your health care professional has prescribed it, then I'd take it.
If I could give you my view, it's that you should just stop thinking in terms of single ingredients, supplements or magical superfoods dreamed up by marketing teams to treat you, and concentrate on the main issue - cutting right down on carbohydrates. Cookbooks can be helpful for some ideas, but essentially, I've found ones that try to recreate the same recipes you've always eaten with low-carb versions are usually disappointing and aren't what you need. You need to experiment without the ingredients you would previously have put in (potatoes, pasta, rice, flour, sugar) and with the ones you can now let yourself eat more of - cream, high-fat cheese, full fat yoghurt, butter, avocados, nuts, mayonnaise etc.
I too wasn't a big fan of salads, but it's amazing how they're transformed with high fat ingredients. As I type this, I've just finished a salad of Spinach, with mozzarella and taramasalata, and bought the ingredients for a stir fry of mixed cabbage, cauliflower, peanut and steak which we'll eat tonight. For breakfast I had full fat greek yoghurt with a couple of fresh ripe apricots, walnuts, pumpkin seeds, sunflower seeds and chia. I have a jar of the pumpkin, sunflower and ground linseed at home which I usually put on salads and along with fullfat mayonnaise it transforms them into a tasty meal not some kind of penitance.
If you approach it right, it's a liberation to eat wholesome, tasty and satisfying food, rather than a burden you'll have to carry for your whole life. I personally, am enjoying food now more than I ever did before and all the other benefits you get from LCHF - more energy, weight loss, and most of all - low blood sugar and the prospect of no diabetic complications to look forward to.