If you want to try therapy, overall I do recommend. No one deserves to feel alone, and at minimum therapy can help with that.
In terms of support for circumcision grief specifically, therapy is hit or miss, and that's being generous. Having high hope for therapy underestimates the systemic nature of the oppression in cutting culture.
Back in the 1800s, should a slave with ahead of his time racial consciousness expect to go to a therapist from the prevailing medical establishment of his day and be anywhere nearly properly understood? Of course not. Just imagine an 1800s slave complaining about implicit bias and white fragility to any authority figure back in day. Not going to go anywhere productive.
The analogy isn't perfect (as I like to say, because circumcision is worse), but I actually think its closer than is often given credit. No authority figure like a therapist is going to properly understand. Therapists for all other issues have substantial identity consciousness training. Therapists go through required certifications and trainings for how to not do micro-aggressions against black people, minorities, women etc. You want to know which topic therapist training complete avoids? Circumcision. Shocker. When you go, even if you get a good therapist, expect micro-aggressions on the topic. Expect the therapist to not really care, to comment about how its no big deal, to be surprised your bringing it up, to regurgitate offensive cutting culture talking points. And that's if you get a good therapist. Despite being well-spoken and transparent on the subject, I've had therapists who couldn't even believe circumcision was the real reason I was upset, and were looking for the "true" reason that must be something I was hiding.
Overall, therapy is good. But therapy is part of the problematic world we live in with systemic oppression and cutting culture. So faith in quality of circ grief therapy needs to be low