I have sudden dizziness when i walk with burning sensation in my throught and vomiting and palpitation but i'm not pregnant what the possible diagnos?

SVT: Your description suggests the possibility of an arrhytthmia such as supraventricular tachycardia or atrial fibrillation. An event monitor exam (24 hours to 30 days) would clarify the diagnosis and permit targeted treatment.

Dizziness: Not enough information to answer. The burning is probably some acid reflux before you vomit. If the dizziness is that severe to cause vomiting go see your pcp. Many different causes to explore.