Seriously - you want a state appointed lawyer? LOL. Just me, but I would not. That is like the fox guarding the hen house. IF you cannot afford a lawyer (as the Miranda portion says) then by all means take what you can get.

As far as what do you say - I thinketh you talketh too muchet.

Here is your problem - you will be under an enormous amount of stress like you have never been before (except perhaps for combat) and you will not likely remember what you planned out and you wil ltalk and say things that you don't remember - you will miss details and critical events.
Also, the phone call you make to 911 is recorded, so you better make sure you don't say you just shot someone - you are admitting to a homocide. I would say someone's been shot, please send police and EMTs immediately. You will likely need to stay on the phone with the 911 operator. I would be silent and confirm you are there. I would desribe your clothing to officers arriving so they know you are the caller. The one who calls is generally assumed to be a victim. The officers are going to ask what happened. At that point you need your lawyer. The best practice would be to say nothing more than I was going to die, but I need to talk with my lawyer. If you need to go to the doctor then say so, but shutup. You will likely have your gun seized too. More than likely you will also be handcuffed and arrested - if nothing more than a Terry stop to secure the protecction of the officers.

On the doctor thing - if you say anything to the EMT's or the doctor, it is unlikely protected speech. The doctor patient privilege invovles information necessary for your treatment, not that you defended your life, etc. Identify your injuries, do not explain the story. Remember, the doctors record things in their notes and on the charts. Your dicussions will be there. Someone will see it and read it.

As for the husband and wife privilege - this applies only to compelling your spouse to testify against you for criminal matters. However, be careful, this privilege does not apply in civil court when the perp sues you.