I have a new honeysuckle plant that has grown rapidly and seemed really happy. However, in the lower portion of the plant the stems are turning yellow/brown and leaves are dropping off. I'm worried it may be a disease that will spread to the whole plant, and I cannot remove the affected stems as it is all of the main stems, so it would mean cutting down the entire honeysuckle. I've attached photos for you to see. I did spray it with a bug and mildew spray as I thought it could be that but now I'm worried it made it worse.
Please advise on what I should do to prevent it spreading or worsening.