Well... That was not a good idea..

Alright so a few weeks ago my car was running low on anti-freeze and not knowing BMW made special anti-freeze, just filled my car full of John Deere tractor anti-freeze. Now a few weeks later the computer is telling me my anti-freeze level is low so I called and found out it takes a special kind. So my question is what should I do? Should I stop driving the car and order some BMW to put in it when the anti-freeze comes? Should I drain it then re-fill it with BMW anti-freeze? Should I continue putting John Deere anti-freeze in it? Any advice would be appreciated. Thanks!