How to communicate that I (45f) have no energy to give husband (45m) the sex life he wants ?

I feel so broken right now. I thought my (45f) husband (45m) and I were in a good place. We were getting big things accomplished - oldest is going off to college in 22 days, we got all the renovation work done, had a great vacation for just the two of us to reconnect, we both even started exercising again. Over all, I was really happy with where we were and how we were handling life.

Until this afternoon. This afternoon I get a series of texts with links to sex toys and a book about adding sexual intimacy everyday. Every. Day.

I’m sitting here trying not to cry because now I feel like nothing I do will ever be good enough. I’ve been diagnosed with fibromyalgia for 10 years - he knows how emotionally, physically, and mentally drained I am nearly 24/7, and now he needs more.

How do I:

1. deal with the crushing depression of knowing that no matter what I do it will never, ever be good enough? I will never be able to make him completely happy. We’ve been married 22 years and I don’t have the emotional or physical strength to satisfy him.

2. tell him all that without it being a massive guilt trip? He is communicating his needs like he should, but how do communicate back that my needs are in direct opposition to his ?

How do I tell him I have nothing left to give?