English is notoriously one of the hardest languages to learn. Don’t worry about getting the tenses wrong. People do that all the time who are conversationally fluent speaking English as a second language. Any native English speaker won’t be phased by it, and can easily tell what you’re saying.
If someone said they maked a mistake, I wouldn’t be confused. If someone said “I was going to the mall yesterday” any native English speaker would know that you meant “I went to the mall yesterday.”
Consider that your mental health situation might be giving you some tunnel vision making it easy to rule out viable paths forward. Honestly, if you can read and understand this response, I would say you are generally fluent. At least with reading and writing.
When mental health is flaring negatively, we have a severe negative attention bias. When things are bad enough, someone could give you the actual perfect solution, and a depressed brain will latch on to the small details that make it sound not so good, and rule it out to be not viable. This is just something that anyone struggling with mental health needs to become aware of.