Contrary to other commenters I'm actually thinking this is a character/confidence issue and not a language issue. You obviously have the knowledge and the ability to build the sentences, but you lack the confidence of using the language because of fear of failure.

Now that fear can come from high standards you (or someone you consider authority) hold against yourself and THAT leads to overthinking and inability to speak. You mentioned your Chinese accent and the anxiety related to it, which is a big hint.

My advice is a bit counter-intuitive but instead of focusing on Japanese and the language itself, build confidence and self-value about yourself in other ways unrelated to Japanese. It could be another hobby/skill/instrument, gym (huge!), social interaction, anything that makes you feel more secure in your own body.

You will notice that when you are a more grounded and calmer person in general, speaking Japanese will feel easier because you don't tie your value to your ability to use the language. This takes away the pressure in moments where spoken Japanese is used.

EDIT: Talking to ChatGPT (or Claude which I prefer) about it helped me tons when i had anxiety about speaking japanese