Lavender has so many uses. It is indeed good for helping to calm nerves and ease stress.
I can recommend some companies who sell already-blended oils in a bottle. You can then use the oil in a variety of ways, either rubbed over your neck and chest area just before bed, or you can use the oil blend in the bath too.
Materia Aromatica is one company I use. Another one is Naturally Thinking. I’m not sure if I am allowed to put the full website address here, but if you Google these names their websites will appear.
Essential oils can seem expensive, but that is due to the cost of producing them and you only need a few drops for them to work on a subtle level. It is a whole subject in itself to explain how they work on the body/mind, but nevertheless an interesting one.
I can recommend a couple of books too, for those who may need some guidance with application of essential oils. But just as a quick reference, they should always be diluted in a carrier oil (Sweet Almond, Grapeseed, Calendula, Camellia, etc) and never applied neat onto the skin.
I have one which I bought from Penny Price aromatherapy.