The only thing I can suggest is perhaps trying to protect it with something that will keep it dry and allow it to still get some sun, like a home made cloche or something similar. You would want to ensure good air circulation too. Not absolutely sure but black leaves might be a fungal prob, so if you remove them then clear the entire area and any that fall onto the surrounding soil to reduce reinfection. Fingers crossed this might help till dryer weather 🤞🏼
Hi Wayne, might be best to avoid cutting back too hard. Lavender normally dislikes being cut back into old wood, but stems can normally be cut back as far as you see new shoots. You’ll have to see what is coming through. The old dog collar sounds potentially good idea (I know the ones you mean 👍🏼) - maybe try it just on the days when it’s going to rain hard. Leave it off on the days it’s gonna be dry and that will allow it to dry out a bit.