Okay, I'm going to assume the facts based on what I have seen so far. Please correct me anywhere I am incorrect on the following:
Ages: W - 45, H - 47
Children: 1 boy aged 16 (18 year old is an adult);
Incomes: W - £3.5k net; H - £5.6k net (assuming £100k gross)
Assets: Equity in FMH of £280k. You haven't mentioned pensions but will assume there is one.
Each divorce is unique so the advice that follows is only general in nature, but the short answer is that if my figures above are correct your husband is being extremely generous and the likely outcome at a FH is going to be much worse for you.
What the court is going to do is look at what your reasonable needs are to avoid undue hardship (some hardship is fine). Your strict needs are going to be a two bedroom flat and an income to support yourself and your youngest son. Even in the most expensive parts of Wales (and as you work from home, you might be expected to move to a cheaper area once your youngest leaves secondary school), you can buy a two bedroom flat with half of the equity and a modest mortgage that on £3.5k net you can easily raise a mortgage against. So, a 50/50 division of the FMH will probably result because there is no reason to move away from equality. For the pensions, they will probably want a pension report so that the two of you have the same predicted incomes arising at the point you retire from the pots available. It will be close to 50/50 but maybe deviate slightly to achieve this.
As to income, £3.5k plus child maintenance will be considered more than enough to meet your reasonable needs. So I would expected spousal maintenance to be terminated quite quickly. He might be ordered to pay some of the mortgage until the house is sold but that will be about it.
If you are not in fact earning £3.5k and this is actually your net income in total with maintenance, the outcome will be slightly different. You will probably get some maintenance for another year whilst you adjust but it certainly won't amount to the £3.8k you are currently receiving unless he is earning a lot more than just over £100k. You will be expected after that to work full time and support yourself.