The issue here is three fold.
one, you’re not giving it enough time,
two, many folks struggle when switching from mounjaro to wegovy.
three, you need to diet.
I’ve been on mounjaro for about 18 months and read a lot of social media posts, I have come to the conclusion that weight gain is either physiological or psychological in the main ( can be both but often one primary driver )
if the desire to lose the weight is there, and the issue primarily physiological, blood sugar, insulin, metabolic issues, then the drugs work fantastically, it is the tool to help you succeed, as your body works as it should thus allowing you to diet.
if the desire to lose weight is there, but there is psychological barriers, binge eating, depression, comfort eating etc, then the drugs do not tend to work for many, as you can push through.
if you have not lost weight in 4 months the truth of it is you’re not eating in a deficit. If you were you’d lose weight. The drugs will not do it for you, not unless you get to such a high dose for yourself it becomes impossible to eat and you make yourself unwell, and this is clearly not advisable.
so the question I’d ask myself is what is stopping you eating in a deficit, even when spending so much money on the drugs, and wanting to give up quickly. It would indicate it is psychological?