If you are staying on the boat at a marina, then get off it and go rent a hotel
room. Right now. Your credit card probably needs some exercise anyway. Once you are off the boat your perspective may change. You will be able to come up with a plan that makes you feel better about the future, near and far.
You may feel foolish for experiencing symptoms of PTSD from what you consider was a minor incident. Nobody was shooting at you. No one was killed. No dismembered body parts
laying around. Not in a war, etc.
But perception is everything. And you truly felt your lives in danger
. You were not wrong. And as the "captain," you feel it was your responsibility, and that you failed by placing your vessel and your lives at risk. That is real enough. You should feel upset about it. It is more than enough to cause the symptoms you describe.
There is nothing wrong or inappropriate about your feelings. So NO need to feel embarrassed about it. But what to do? You have to DO something.
First, understand that as bad as you feel now, it will get better with time. It will pass.
"Time heals all wounds. " Sounds simple, but it is true. So make an exercise out of not thinking about it as much as possible and eventually you will find yourself thinking about it less. When you have those thoughts, push them out of your mind, and go do something else. Time will pass. And the symptoms will ease. All by themselves. Tomorrow will be better than today. And the next day better than tomorrow.
Some mental health
"experts" will disagree. They will want you to talk about it all endlessly so you can "work out all your issues." Mostly they will want to "work out" your bank account and insurance
in return for continuously having you dredge up and relive your most frightening experiences. Keeping them all nice and fresh. Preventing your normal processing and forgetting. Then they will prescribe drugs to calm you down. Drugs you cannot easily stop later. Drugs they will want you to stay on for the rest of your life.
Your mind has a wonderful mechanism called repression. Your mind will bury these events
and forget all about them. If you let it. So know that eventually you will be ok. Just believing in that should help you.
Second, decide if you want to sail again or not. No law says you have to ever get on another boat again as long as you live. If you decide to never do it again, then that particular threat and source of stress is immediately gone forever. No boat, no problem. Ask someone else to sail it back. Move. Sell the boat. Take the bus home. Or rent a car. Buy a caravan and go camping instead. Done.
If you decide you want to continue sailing, then do what someone above suggested.
Arm yourself with knowledge. Read, study, take lessons. Practice in easy conditions. Improve your skills to the point that you become confident that you will not make those particular mistakes again. You will make other mistakes, but you will know how to handle them. Your biggest mistake was really simple. You went on the wrong day. In a machine you did not know how to operate.
So you have already learned;
lesson number one: learn how to work the boat.
Lesson number two: check the weather.
Maybe this doesn't help you this week. So leave the boat where it is for now. Or have someone else take it back. Don't force yourself to do something you are not mentally prepared to. It is not war time. No one's life depends on you sailing anywhere this week. Forcing yourself, and your girlfriend, and your dog for that matter, back to sea may make it all worse. Or maybe it will cure you. But it could go either way. And it won't be fun.
If you are determined to go and you must go now, then go by yourself. The will remove the stress of being responsible for everyone else.
Third, if you feel you are truly in danger of a breakdown, if you cannot function, if you cannot sleep at all, crying, having violent temper outbursts... then go to a hospital emergency
room. There are drugs that can be prescribed to calm your symptoms within 20 minutes or so. Quick acting and no lingering effects. Alcohol is not one of them.
If you are really having a hard time, then go get some emergency
help now. And take your girlfriend with you. The dog will be ok.