Apple Music issue

I am trying to set up an Apple Music account and I went through that who process and was able to make an account. When it can to the time go start my 3 month free trial I clicked it and put in my Apple ID password and then a message popped up saying I can’t make one because the offer expired and I already had a free trial which I didn’t. I went into my settings and when to iTunes & App Store and clicked the music button and it’s saying that my device is already associated with another Apple ID but I had my old Apple ID connected to my phone with all my other music that I had downloaded but I can’t get into that one. I also got an email from Apple Music saying that I can get a 3 month free trial.