the fizzing and smoking is only a sign that you have an HCL salt, which is just basically any chemical in its stable form
if it turned straight black instantly and fizzed and smoked, that should mean that you have some very high quality MDMA :D
be careful though, DXM turns a dark grey and will almost always fizz iirc, so do all the regents and post the pics here, but so far it seems like you have nothing to worry about