What is this feeling? i get too nervous suddenly and my heart starting to beat fast, sometimes i get dizzy and difficult to breathe?

Anxiety: Does the fast heart rate lead todizziness and then you get anxious or do you get anxious first the the other.For anxiety relax and try to calm down/meditation,exercise helps as much as medication for mild anxiety.However may need counseling and possible meds.If medication ,benzodiazepines work well but are addicting so only short term if needed while SSRI getting up to therapeutic range.see a doc