Is there still mildew on my clothes?

Hello, I recently found black marks on my towels and some of my clothes after taking them out the washing machine. The apartment's maintenance came to check it and said it was mildew, cleaned the machine with white vinegar, and left. I washed everything at my house's washing machine with white vinegar and detergent, but didn't realize that those cancel each other out. I'm scared that the mildew is still on everything, even though pretty much everything (besides the towels and one piece of clothing) are stain free and smell fine. I put everything but the badly affected items back in the wash, and put distilled white vinegar in the fabric softener slot because apparently it'll dispense at the end and not interfere with the detergent. I put the temperature setting as hot. Will this get rid of it if it was still there? Will it spread to the washer and other stuff? I have bad OCD so it's making me really anxious. I read online that you're supposed to soak everything in white vinegar before throwing it in the machine but will this also work? Thanks.