I'll also add a few things that helped me for people who may read this thread at a later time:

• Don't give up
• Keep communication going from the second you are told that your spouse wants a separation until some sort of resolution happens
• Don't plead, beg, cry a lot, etc. Be rational.
• Find a person of the opposite sex who can help you better understand points of view
• Make sure to talk to people who are both married and divorced for advice
• Write down your thoughts and share this writing with your spouse and ask them to respond. Then talk about the writings. By writing stuff down it gets you to really think about what you're saying and organize your thoughts, all while making it so you're not reacting in the moment.
• If the only reason you're trying to stay in the relationship is because you can't bear to think about being apart from your spouse, then you need to find more reasons to stay in the relationship. Your spouse will rarely accept that as a reason. In my case, I recognized that I will become a better person now that she's identified some of my character flaws, and that by becoming a better person we'll be able to enjoy our relationship more.
• SEE A MARRIAGE COUNSELOR, BUT MAKE SURE THEY HELP NOT HURT. Our counselor is AWESOME. However, one of the counselors we saw before we picked this one several years ago told my wife and I that I was a jerk and she would be better to leave me. Not all counselors are built the same. You may have to try a few.

And here are some of the things I suggested to my wife to make sure I don't screw up this chance.

Issues to work on

• How I react to conflict and being scary
• Saying mean things
• Laziness
• Selfishness including trying to get “my way”
• Finances

Communications

• We go back to you writing and me responding in writing. Once initial issues have been laid out, we may go to verbal communication, but I would leave that choice up to you.
• The writing would be completely open, honest and incorporate true feelings. If you identify an overarching or repetitive issue it would be great if you could communicate this to me.
• If you have a big issue and want to communicate it verbally, I will let you tell me everything you want and will not have a negative or aggressive reaction. If it creates a bad feeling on my part, I will wait until I process everything before I respond. This may be later in the day or even the next day. The goal is not to respond in the moment and to truly consider how you feel, while also making you less scared of communicating with me and how I’ll respond.
• I will always respond to something you raised by the next day at the latest. We’ll continue to talk about it every day until we are both OK with the result, even if it takes a month (which I certainly hope never happens).
• When we disagree on something, I won’t always argue my point and try to get what I want. I will work to understand the reasoning behind what you want, step away to consider it if needed, and realize at times it’s good for you to get what you want without compromise and at times I’ll get what I want without compromise - and sometimes we’ll find a compromise we can both agree to. I may ask for your help here to tell me that I’m being argumentative.
• If I realize I said something stupid, acknowledge it and apologize. If you hear me say something stupid and I don’t seem to realize it, tell me (**** you or asshole is acceptable). Over time I will become better aware of what is ok and what’s not ok to say.
• Reduce the number of times I leave a conversation because I’m hijacked. Do my best to work through it. If I get to the point where I regress and feel like I’m going to say something hurtful - then it’s ok to walk away for a moment and process the conversation - but then come back to it. Don’t leave things hanging.
• On a weekly basis, you’ll give the relationship a ranking of 1 to 10, 1 being terrible and 10 being amazing. If the week was great but you’re pissed the day that you rank it, it shouldn’t be a 1, but it also shouldn’t be a 10. At your discretion, you’ll write why you ranked the week that way. This will give me clear and timely feedback on how we’re doing - and whether I am doing the right things or not. I could do the same if you’d like. We could also verbally talk about the rank, but I’d really like to make sure as much as possible is written down.

Finances

• Discuss the boat. I would prefer not to sell it but I will be OK with this and not be resentful if that’s what we need to do. I think there are pros and cons but I will be OK with what is decided. (I later changed this to.. we're selling the boat)
• Look for more ways to save - look at my spending and “what do I want to spend” vs.” what do I need to spend”.

More practical stuff:

• We’ll put a schedule together for making dinner. I’ll take your suggestion of some time ago and maybe make dinners on weekends to refrigerate so they can just be heated. Whomever doesn’t do dinner washes the dishes and they will be done before dinner the following night.
• We’ll put a list of stuff together for keeping the house clean.
• I’ll work on going through everything in the basement and work to keep up a schedule of one box or area a day.
• I’ll start exercising in some shape, fashion or form. I would appreciate your help with coaching on this.
• We’ll do our best to try to do something at least a couple of times each month if not more. Get out of the house. Do something together. Farmer’s market? Apple picking? Going to some town again? Doesn’t need to cost anything like going out to dinner. The point is to spend time together and have fun as a couple.