Spring is the time when we look forlornly at our lavender plants, wondering if they have survived the winter. Here in Connecticut, this past winter was worse than normal, with (what seemed at least) excessive amounts of rain and general yuck ( farming term). Couple that with a late spring (30s - 40s in April!) and our lavender, probably like yours; is not exactly looking bountiful.
Even under the best growing conditions, lavender is a notoriously slow starter. We've fielded numerous calls from gardeners worried if their lavender has made it through the winter. The best answer we can give you is the same one we tell ourselves, it's too soon to tell. Our plants are just now starting to wake up. Mostly grey with just a few sprouts of green starting to show.
Best is to just wait it out, give it time, don't start hacking it down (that only stresses the plant). Once it starts to green up (probably end of May) than you can do some selective pruning of obviously dead stuff, but for now, just leave it be.