That's so sad. I had problems, too. For many. many years, over 15, I tried to grow lavender. Finally I bought some marked down, just threw them in the soil with some sand added, and left them to their own devices. And this technique worked. No additional watering and no fertilizer. The ones I have are French, or Spanish lavender. I don't know if that's the reason I could grow them. They might be easier than the English.