First thing you need to do is prepare a budget and expenditure of everything going forward. For you and your child. Every tiny little thing, haircuts, family Christmas presents, secondary school trips, absolutely everything. Go through your bank statements for the last six months, see where your money has gone.
Then, see where you can pare things back.
You need to get a pension sorted as you have no assets. You need life insurance and critical illness cover. A will. This all costs money. Get the figures in place now. Make sure you claim child benefit, you have the single persons reduction on council tax. Go on entitledto.com and check these things.
How are you going to pay for your old age?
What you do now will matter then so you've got to get it right. He'll get a company pension presumably, he'll be able to save from his lovely big salary. You won't.
It's far from being grabby. What's the statistic? Two-thirds of pensions living in poverty are divorced women?
The cost of living is rising. Maintenance payments are linked in to inflation. In effect you will get less as the cost of living increases. If mortgage rates go up, your rent could go up, your maintenance won't.
He'll be alright with his six figure salary, the shares and the bonuses. What you do now you need to get right.