On September 1st, I asked my professors to write LORs for a grad program I'm applying to and told them the deadline is October 12th. It's actually a rolling admission, but I said October 12th to get it in ASAP. My application isn't considered complete until they get all components of the application. Both agreed. I sent follow up emails: One on October 5th and one on October 12th as reminders. One professor submitted it and emailed me to let me know. The other still hasn't submitted it, so I sent him another letter today and he hasn't replied. He usually replies ASAP.
My friend once got a LOR from him and she told me he submitted her letter like a month late.
I'm really stressed out. I'm not on campus this semester so I can't talk to him in person. What else can I do?