What have people done that’s really helped with weightloss?

I need help. I’ve tried everything but nothing works. I’ve tried slimfast-lost a stone but gained back straight away as started eating I’ve done slimming world lost abit of weight but would gain some weeks lose the next I’ve tried keto but can’t afford it anymore I’ve tried calorie counting but lost nothing I’ve gone to the gym 10000 steps everyday I turned vegetarian to save calories

No matter what I do I either lose no weight and just gain or I lose weight but gain it back straight away. What can I do?? I’m debating ozempic at this point I’m so desperate