I've been there and from my experience all I can say is that if you have the will power to eat right, go to the gym and really dedicate yourself to lose the weight yourself then go for it. For me it was different because I thought I had the strength to do it myself after I was approved for surgery last year, but it was really just because I was afraid of the drastic change I was about to face and I still wasn't mentally or emotionally prepared.So Yeah, I ate right, went to the gym, lost some weight, but then I hit my plateau I couldn't lose anymore then gained it all back. again, that was just me. but now I'm one week out and to be honest getting the sleeve was the best thing that ever happened to me. It is a BIG change, but it's one I made to not only better myself, but my health as well. So if you feel like you can really do it on your own, then go for it. But if you're just scared and trying to find a reason not to, don't be scared. It'll be fine, you just have to make sure you mentally prepare and keep in mind that this is a tool. It's still hard work regardless, but you'll be healthier in the long run.
side note: I used to LOVE eating and I was always hungry. Now I'm not hungry whatsoever and I'm SO happy about that lol. I don't feel like a prisoner to food anymore, but again that's just me. I can't speak for anyone else or you. In the end it's about what you really want for yourself and what will make you happy and healthy.