my opinion: you are spending emotional energy on judging yourself. This energy is then not available for your goals. (Emotional energy is like a limited supply of money: spend it wisely, don't throw it away.) It undermines your motivation, and your faith in your ability, without which goals are impossible to achieve (literally). This is especially serious for weight-loss, because many people eat as a way to stop the feelings that the above creates - you need an alternative way to feel good about yourself, instead of eating.

You sound desperate. If you are, I have a suggestion that will help. But you'll only be able to do it if you are desperate:

Set doable goals, do them, and celebrate them.

1. Start off with clearly doable goals - no challenging or stretch goals! A good guide is to estimate what you think you can do, then halve it. [note: if it turns out that you can't do it, it was not a "doable goal" - start again with an easier one] To give you an idea of just how easy I mean, an example is: to make a mark on a piece of paper.

2. Doing them means to remain focussed on them. No moving the goal posts! Don't be distracted by other tasks; nor by thoughts of whether you can do it or not, nor by whether it's too easy etc. The way to prevent distractions is as in meditation: acknowledge them without anger nor fighting them, and gently shifting your attention back to the here and now.

3. celebration means something very specific: you recall (visualize) the state of events before you began; and then you compare the visualization with how things are now. And you notice that there is a difference - a change in the world - that is entirely due to your power.

The key is self-appreciation. You thought I was melodramatic when I said you can only do this if you're desperate? No. Setting a reasonable goal, doing it, and celebrating it is really that hard. It requires a particular kind of self-discipline that (according to your post) you presently don't exercise. You can improve at this - if you're desperate enough.

every great achievement is made up of a number of small achievements