Processing / describing emotions – I know the theory but it doesn’t work for me if I try by myself

I’ve seen the power of processing an emotion through describing it on coaching calls, in the podcast with Bev and Brooke and have experienced myself with the help of my 20 minute session coach.
It has been very powerful when I work it with a coach and I can immediately feel the relief and “flowing” of the feeling specially if it is a negative one.
But when I try doing it by myself I just “don’t feel it”, it just doesn’t flow.
Example: if a coach on zoom asks me about it I immediately feel the tears flowing which is a sign that I am feeling it and letting it flow, and when I try to work on it myself, it just feels stuck, like I have this invisible shield preventing me to tap into it.
Any suggestions on how to practice this by myself to be able to feel and process the feelings?
Thank you and Happy Holidays.