I'm sorry to hear about your husband. I hope he's ok. I'm also sorry that you feel like you're always standing in his shadow. It sounds like it's a bit harder for you to get out there and socialize than it is for him. And that's totally fine, but I wouldn't get down on yourself too much about it. I'm certain that people are not secretly wishing it was you that had gotten sick. I understand it might feel that way at times, but I just don't think most people would think such a horrible thing.
Anyway...sewing is a great idea! I used to sew a lot when I was younger. It's very relaxing and can be a lot of fun. If you get really into it, you could even try to sell some of the items you create on sites like etsy.com. People love to buy creative, handmade things that come from the heart! Let us know how it goes!