I don’t think there is such a thing as “permanent harm in one’s ability to trust”. Although it can certainly feel that way, the capacity to trust isn’t something that gets permanently damaged. There is always the potential to heal from relational trauma and learn to become more resilient, and find a way to understand and come to terms with what happened, and also work on your own ability to discern in what situations and to what degree you feel it is safe for yourself to risk vulnerability.
So if you take out the assumption that “ability to trust” is an on/off switch you must avoid ever tripping in life, then damage to trust becomes a painful but temporary risk of all relating, and part of the growth of relational skill.
I do think that tending to the relative fragility or lack of relational skill (part of which is inability to determine or set healthy boundaries around one’s own vulnerability) is a crucial facilitation skill and it can be risky for a bunch of relatively low-skilled friends to get together and decide to play around with vulnerability. Not only is the lack of skill a problem, but circling with people with whom you have pre-existing relationships is usually a lot MORE complicated than with strangers. This is because all the unspoken stuff starts coming out, unspoken agreements to not discuss certain things start getting violated, and this is all happening within the high-stakes situation that you care about these people and want to maintain the relationship. All hell can break lose rather quickly.
So I’d recommend (a) get comfortable with one on one therapy first, as it is the safest space you will find and much safer than a group of friends and then (b) get comfortable with a well-facilitated group of strangers led by someone with some therapy-type training and then if you want to (c) invite your friends to that well-facilitated group, and then only after that (d) try circling unsupervised with friends. And even after all of that, expect it to get rather messy, and have some agreements before hand about how you will handle that mess when it happens. Like, “here is our repair procedure for damaged trust”.
In other words, do not underestimate how tricky authentic relating actually is, and how much our day to day habits and cultural and social norms shield us from having to be any good at it. But, also don’t believe that you can’t recover and learn from socially-induced pain, shame, and embarrassment, because you absolutely can. Resilience is absolutely a thing. It is like a muscle though and takes time to build so go slow and take care of yourself.