Hi @Confusedandhormonal I think it's useful to remember that you can stop taking it if you don't get on with it, after one dose if you want to. So it's not a decision you can't change your mind on, once you've got some more information and experience of what it is like.
It doesn't work for a small percentage of people. It's unlikely that will be the case for you. If it is, you could try Wegovy which is similar, and can work for people where they don't get on with Mounjaro. If neither work, well, you are now armed with more information about what works for you and what doesn't. You could then look at trying other weight loss approaches instead. Which is the same position as you are now in, so you won't be in any kind of worse position other than having spent some money. But I think spending money in an effort to improve your health is worth the try even if you don't get the results you want.
If you genuinely think you have failed as a human being, then it makes the argument to try weight loss injections stronger, not weaker imo. Why would you not want to try an option that will help you moderate yourself, that's designed to do that and is proven to be effective at it?
For context, I've been on Mounjaro for 6 months, starting at 22 stone. I'm now about the same weight as you and continuing to lose weight. I am so very very glad I made the decision to start back in July. Yes, I've had a few side effects here and there, but they were not for very long and totally manageable. Not something that would deter me from continuing to lose weight.
The mental benefits of no longer having the daily, minute-by-minute constant negative internal self talk about my apparent lack of willpower cannot be underestimated. I don't berate myself or even care about what I've eaten or not eaten. I don't obsess over food, I just eat when I'm hungry and stop when I'm full. Lots of spare mental energy to use on other things! Plus all the other physical benefits of having lost so much weight too.