I'm in no way a plastic surgery connoisseur, but I've done three separate (small?) procedures and a couple other non-invasive stuff like lasers. I can honestly say I stress less about how I look now.
But not because I necessarily look much better. Most of the changes are very small and sometimes they make a certain flaw look better but create more. Or, like my face lipo, I looked much better for many 4 months and then I didn't eat properly and regained all the fat back in my face.
I think plastic surgery partly kinda made me feel like I'm not stuck for life with all the flaws I have and with enough money I can alter those flaw at least somewhat whenever I decide to. Another part is that by being immersed in the support groups, I learn that everyone has something they see an imperfection in themselves so I don't really take my own physical flaws into account for my confidence anymore.
I also now see these surgeries as investments. Because I live in Thailand where people really have increasing degrees of "lookism" where how well you are treated and how much opportunities you are given is related to how close you look like a certain ideal image (i.e. for girls: pale skin, very thin where curves aren't really necessary, elongated and v-shaped face, not super short and not super tall). So now I do it, not because I'm insecure anymore, but so I get more opportunities. In a way, almost equivalent to making your hair nice and putting on a professional, polished attire for the workplace to be respected and taken seriously.
I think it's important the understand the 'why' you think you need more surgery. If you always have a sort of list of what you want surgery on and you do all that (plus the fixing/re-do procedures) but afterwards you see more "flaws" to be fix, it might be an inner thing that you have to come to terms with. For me, I have a very specific (albeit very long) list of what I want to improve and that list hasn't changed. It might be important to be honestly look at if this is more than physical changes. It could be a body image dysphoria or perfectionism as well. Above all, I think it's important to also work on non-physical things. I found that helps my self-esteem a lot.