I did my first divorce myself, the local court were very helpful giving me the relevant forms. We were quite young and had no children, and agreed amicably to split everything 50/50.
However, at your age I would get some legal advice. Is there a divorce forum where you could find recommendations for a good local solicitor? That can make so much difference.
I agree about taking copies of everything now, before you speak to him. Including pensions, premium bonds etc. Consult a solicitor for advice before you speak to your husband, so you know where you are.
You could have 30 years left. The start of a wonderful new happy life. Go for it.