Hello, I am Rafael. Thanks for asking your question - I'm here to support you. (Information posted here is not private or cofidential but public).
I am sorry to know about this concerning situation.
Most people in your shoes would feel overwhelmed by finding out there was not real honesty but betrayal while in relationships, even more with two different people in such a short period of time.
Affairs happen but make of them truly destructive and lead to hopeless scenarios is the partner's choice to keep dishonesty, and not taking real responsibility for her own actions, and when that's the case, to keep trusting would nto be a good idea but very naive and self-sabotaging.
Thank you - what can I do to rebuild my trust in her?
There would only be hope if you still happen to feel like you can and want to work on healing the relationship and if she chooses to start being totally honest and accountable in the relationship. It's obvious she has personal issues leading to the problems in the relationship, issues she needs to address, ideally with counseling support,`since this is not about an isolated episode which led to mature positive change, but she continues to show the very core issues of lack of honesty, respect and responsibility, essential for any relations
hip to develop as a healthy and fulfilling one.
Trust should be deserved and built through consistent actions based on respect, honesty and commitment, to trust without those concrete requirements would lead to self-sabotage so to further infidelity.