I think perhaps you should see a doctor at this point if you can, just to be safe. I don't know anything about varicose veins and I definitely haven't had any noticeable changes to my breath. Since stopping eating animal products I have had to work harder on my skin but in my case that also roughly coincided with a change to a different method of birth control so I mainly put it down to that.

Also, as other comments have pointed out "detox" isn't really a thing - you have a liver etc that manages your body's waste and if you really had a build-up of toxic compounds in your body that you needed to get rid of, well, you'd need chelation therapy or something and you'd probably have a lot worse symptoms than what you've described.

Of course making a big change to your lifestyle and specifically diet in this case is bound to have some impact and will be different for everyone, but I would expect that to be mainly gastro-intestinal. For any other health concerns it's worth making sure you are getting as good nutrition as you can and supplementing anything you need but can't get from your diet. For most of us that means B12 at a minimum.