I steeled myself to read this post in the most charitable possible light. Yes, lockdown most likely has some death toll. But the specific points you're making are very dubious and also very recognisable as the effect of consuming specific kinds of media.
Firstly, the point about "not getting as much exercise" is frustrating. Back when we didn't have data on this, it was annoying to me to hear people's absolute conviction that (a) people would exercise less and (b) the effect would be so large that it would lead to a decrease in obesity significant enough to offset the number of life-years lost to COVID, especially since the lockdown personally prompted me to start exercising MORE due to my new surplus of idle time. We now have some suggestion that for previously sedentary people, it led to more exercise (my experience) and for previously active people, it led to a decrease. I'd love to see any suggestion that the net effect of this was so colossal as to produce the adverse health outcomes of whose existence you seem so confident. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7312512/
> In Australia, an additional 4000-7000 suicides were projected
At least in Victoria, it seems like these predictions were unfounded. Of course, that is not going to stop people from repeating this talking point. https://www.abc.net.au/news/2020-08-27/no-spike-in-suicide-r...