Rescuing a much-beloved lavender?

Rescuing a much-beloved lavender?

Hello all! So I have a lavender plant (L. angustifolia, Munstead) that's about 8 years old, and did wonderfully all of that time. However, towards the end of the summer last year, much of the growth started shriveling and turning grey, from the bottom of each stem up. I belatedly figured out that this was most likely due to excessive moisture - I live in New Jersey, so the weather's very humid, in addition to last spring being unusually long, cold, and rainy. Now, the plant looks like it's survived the winter, but it's still looking pretty sickly - all of the old growth is shriveled and/or cold-damaged. Cold damage I'm used to seeing, but I'm anxious about last season's overwatering having caused irreversible damage. Are there any steps I can take to make sure the plant will make it this season? Am I just panicking? Thank you in advance!
plant ID

plant ID

The Curse of the Black Thumb

The Curse of the Black Thumb

Azaleas

Azaleas

Help…

Help…

Asiatic lilies

Asiatic lilies

I dont have a garden…

I dont have a garden…