@Imakitchensink sorry you're going through this. I was having very similar feelings for a quite a while (for reference, together 12 years, married for 5, 2 young DC's)
Over Christmas time (awful timing!) things just got too much and I ended up telling him how I felt, that I wasn't happy etc. I hadn't felt sexually attracted to him for a while, I felt miserable and grumpy when I saw him, anxiety had got quite bad, couldn't get myself to do things day to day, take the kids out etc. Something in me clicked when we were on holiday in California (from the uk) and were on the beach and I just felt an overwhelming sense of not wanting to be there. He was obsessive about sex (it felt like to me) and I felt like he was always talking about it, grabbing me, making comments and I hated it. He also lies a lot about little pointless things and I'd never been able to trust him fully. But he was generally a good husband, wonderful father, good provider, loving etc.
We're now separated and have lived apart since April, a lot of crappy stuff has happened between us since January to now (too much to go into, but showed I had the right to question a lot that had gone on in the relationship and be untrusting of him) and I am so much happier, there are obviously a lot of struggles and new challenges to deal with, but I myself am happier, my children are happier because I'm calm and enjoyable to be around and do things with them, I don't have a lot of the anxiety I'd had for the last however many years. We have a good relationship despite some of the stuff that's happened and always put our children first, all spend time together and show them that there is still love between us.
All I can suggest is maybe that you trial a separation? Perhaps even stay in the same house (we did, we never saw other people or anything, but the space of sleeping separately, not cuddling up etc gave us a natural progression to the decision we made to then live separately) good luck, take time, don't rush anything 