Smoked 30 cigarettes a day and now switched to vaping. will this help with breathlessness and wheezing as stopping fully is difficult due to anxiety ?

Doubt it: The symptoms are triggered by a natural reaction of the lungs to irritants you inhale. You may have true asthma or a similar issue, but your lungs don't like what you are doing. Vaping still sends what the lung considers irritants into the lung tissue. I would expect it's natural defense reaction to remain the same. You need to find another way to deal with anxiety that avoids the lungs.