Hello and welcome to the forum. Thank you for your question. Congratulations on stopping smoking and beginning an exercise routine. Please talk to your doctor about this to make sure it is appropriate for you. Every person is individual in terms of how long a positive effect will be seen but you are clearly working in the right direction. Have you since taken your blood pressure since beginning your new program? What are you readings? I do believe you will see a positive effect from your lifestyle changes.
In terms of cutting heart disease by quitting smoking, the rule of thumb is that you will cut your risk in half by not smoking for a full year. https://www.medicalnewstoday.com/articles/317956.php.
I also like this article in relation to exercise and naturally lowering blood pressure. https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/in-depth/high-blood-pressure/art-20045206 The Mayo Clinic recommends that you monitor your blood pressure frequently to see what effect your new regime is having on your BP. Do you have a home monitoring device?
Please continue to work with your doctor and let us know how you are doing.