Currently, COPD is not curable. The symptoms however can be eased. (As you have already experienced.) If you do not put any more smoke in your body, the symptoms may vanish all together and you will likely not progress to the later stages or other related illnesses like emphysema. I have seen people with severe COPD who were on oxygen make the switch and within a few months reverse the symptoms to the point of practical non existence. This has nothing to do with
vaping and is all about not smoking.
Whenever you are diagnosed with any disease it is important to learn as much about it as possible. Although it is believed that COPD is primarily caused by the high number of free radicals in
tobacco smoke there can be other less obvious risk factors that can contribute to or irritate the condition. Avoiding nail salons with poor ventilation would be a good idea. Limiting your exposure to fumes of any type in general really. That means no painting your living room without some sort of mask. That means you don't want to work at a toll booth where you will be inhaling copious amounts of fuel exhaust. Generally speaking you want to avoid putting yourself in environments where you are exposed to an overpowering smell of fumes. At 1.5 months it is probably reasonable to expect further improvement. But everyone is different. This is a serious medical condition and you should definitely continue to see a pulmonary physician even if your symptoms vanish completely.