I'm a little surprised that a previous poster has been accused of being passive aggressive for saying that no, it won't cause damage, it just means reduced benefits.
It was a perfectly pleasant, reasonable post, addressing the emotive "damage" point and giving a factual, considerably less emotive response to a direct question by the OP.
I agree. It is highly unlikely that a baby in the western world will be damaged by FF, but it will gain fewer of the proved and possible benefits of breast milk. You need to weigh up how strongly you feel about those benefits compared with your own mental wellbeing and ability to function.
DS1 was mix-fed from an early stage and fully FF from about 4 1/2 months due to feeding problems that we never managed to resolve. DS2 was EBF to 11 weeks when an undiagnosed tongue-tie kicked in and he stopped feeding altogether. We had to introduce formula and never got completely off it (save for a couple of weeks after weaning for some reason) even though he went back to mainly BFing after he was snipped. I was gutted to have to give him formula and we tried absolutely everything to avoid having to do it. But we did what we had to do and he had mainly breastmilk for nearly 8 months.
Would I have preferred him to be EBF? Of course. Can I live with him being mix-fed? Absolutely.
I would seek out any help available before switching, if EBF is important to you, but if things really are getting bad then just make sure you are confident with what you want for you and for your baby, make the decision and don't keep looking back and wondering if you did the right thing.