I realized a thick metal stitch coming out and hitting the skin. Should I wait until my Dr's appointment to resolve this?

I would definitely let your surgeon know about this.  Nobody but your surgeon knows what that is. Don't take advice from strangers on the internet.  

The suture you are feeling is firm, but it is not made of metal.  Call you surgeon and explain to him/her what's going on.  They will likely want to wait until the original post operative time frame that was set, but they may consider removing the one suture that is causing you discomfort. Sutures by themselves, do not cause septal perforations. Communication with your surgeon is very important. Good luck!