Hi Sarah C
I am so sorry you are experiencing this, not only does it make you feel like you have no control but it is very embarrassing. I too have been in this situation and it was also at work, one episode had my almost hyperventilating and crying with noise coming out that was humiliating over a spreadsheet.
This had to stop... I took time to try to assess what the root causes were and for me I felt totally I accepted by my new work colleagues, I was so much older and felt like I didn’t fit in, this lead to be questioning my work and slowly seeing my self confidence going down the drain. I was so full of emotion that it had to come out, any small hick up and I burst into tears... this is not me!
I left that job pretty quickly, I am not saying that you should but some time to sit and maybe write down all you are feeling and what things set you off, if you know that is, you may not and that is fine, maybe a chat to tour manager to get some feedback if you are concerned how you are performing and to let them know how you are feeling and to get some support.
Emotions always find a way to shine.. good and bad. I hope you can be kind to you and listen to your body telling you it is full.
I hope to chat to you some more and support you through this, to comfort you in this time.
Hugs to you Sarah C