You have no need to feel guilty whatever you choose. Our society is set up very poorly for BF and it basically means you have the odds stacked against you before you start. Plus, while it's true that if you are making a direct comparison between breastmilk and formula milk, breastmilk has advantages, that is not realistically the only thing which changes. If you take the bigger picture into account, in terms of things like convenience, mum's mental health, or many many other things all of which will be different for each family, it's not so clear cut. Sometimes there are other factors which are related which mean that overall, the decision weighs in the direction of formula or mixed feeding. And that is FINE. OTOH, sometimes people really do want to breastfeed but they are being given the wrong information or insufficient support, and I think that's a shame - it shouldn't be the case that someone who is new at breastfeeding not only has to get to grips with the breastfeeding itself but also has to seek out and evaluate their own support systems with this. It should not happen that way. Unfortunately that is often the case (so if you want to continue but struggle to find the right info/support it can be worth pushing through to find that).
What can help is: If you could imagine being able to bottle feed but have absolutely no guilt about it knowing it was the perfect thing for you, how would that feel? Relief or still something bothering you?
And if you could imagine being able to breastfeed easily without any difficulty, how would that feel? Great, or still something bothering you?
Thinking about both of those scenarios can help you work out what you feel about BF/FF as options without the noise of what other people think etc. Because ultimately by the time children are at school nobody cares which way they were fed and it doesn't matter. OTOH if it's important to you, then it's important and shouldn't be dismissed. So you should choose and pursue what feels right to you.
In terms of the relentlessness, this absolutely does get easier, it is not so intense forever. It is much more frequent and difficult when you are getting used to it, after 6-8 weeks things get easier and then they will get easier again at later points.
I am small busted so perhaps other bigger bust ladies can advise but I do feel like feeding discreetly becomes easier as you get more used to BF as well - at first it's a whole palaver with getting into the exact right position and so on but later on, you really can just sort of aim them vaguely at your breast and they do the rest themselves, which is much less stressful and you don't have to expose a lot of skin to feed at all. Currently - do you know the double top method? This is where you wear a stretchy tank top with a low cut front underneath a looser blouse or t-shirt. Lift the top layer up or unbutton, and pull the stretchy layer down. You can even cut the tank top to be lower or the neckline to be larger if you need more space as it's an under-layer meant basically to cover your tummy if you feel self-conscious about that.