is There any way your wife could increase her hours/business. Your son is almost 14, I’m presuming he doesn’t need childcare or for your wife to be there at home whikst he’s at school.
Has your wife explained clearly to you why she wants to separate?
At the moment you’re probably feeling like a rabbit in headlights, but you will find your path through this.
I’m unsure what she meant by ‘sort your shit out’
Does she expect you to have moved out before she gets back? Also, in terms of legal advice, there’s not much you can sort over a weekend.
I also think that mum taking son away for weekend is saying ‘mumis the good guy, dad is the bad guy’ At almost 14, you both should be holding your sons hand through this. He doesn’t need a weekend away. I expect your son will be worrying about you the whole time, being left alone and told you’re not wanted anymore.
Are you and your wife fairly amicable most of the time? Is there any way you can see the work in house being done to the completion. This could add value to the house should a sale need to take place.
Whatever you’re feeling, don’t be frightened. It’s an adjustment, but you can do it.
I left my husband 12 years ago. He was an aggressive narcissist. I left him with everything. I just took the 3 children, a small amount of cash from the equity of the sale of family home and rented for 12 months. Best thing I ever did.
The new start was so invigorating once I’d got my head around it. I went back to work and stood on my own two feet. I’d much rather be by myself available for new opportunities, than live with someone who showed such little respect and was causing me to question myself as a person, as a mother.
Your son will of course prefer his parents to stay together, but if that can’t happen, he’d want you both to be happy.
As silly as it sounds, get a pen and paper and brain storm. At first, you’ll draw a blank. Ideas will come. Some will look promising and some will look gloomy, but the gloomy ones are the ones to avoid.
If you can, hand on your heart, say there’s nothing you can do to resolve your marriage, then let it go.
If you think there’s a chance, then go for it. What have you got to lose?
Maybe write a letter, but don’t write what you think you should or what you’ve said before. Let yourself go and write from the heart but apply no pressure. Show her you respect her and want what’s best for her. Don’t write all about yourself.
However she responds, accept it. Don’t question it.
I so hope some of this is helpful. You will be ok, so don’t lose sight of that 
Ps, if you do try and resolve things, avoid flowers, sex, chocolates etc. So expected. Try something meaningful she won’t expect. Get into her heart if you can.