Shera,
The important thing with the finances is to a: try to keep emotions out of them (very hard) b: to keep talking c: to be fair and d: both do your utmost to make sure the children's welfare is the priority. Who did what to who is of no relevance when the finances are looked at - except in the most extreme of cases where one party has say, physically damaged the other so they can no longer work.
There seem to be 2 financial issues here. First how are your finances such as house etc going to be divided on divorce and second what are you going to live on.
The first point is all about assets division - it is not always a simple split. Have a look at some of the threads about fair settlement to see the sort of information you would need to provide for wikipeeps to give you some clues about what is fair. Below my signature I have reproduced the relevant bit of law that sets out what is taken into account.
The second point is income. More than 4 eligible children at CSA rates = 25% of stbx's income. Is that what you are getting? And things like spousal maintennace - money for you - would depend on how much you can earn .. now and in the future. It sounds like, if he is earning, there is a possibility that SM could be an option at least in the short term while you are re-training. You can apply for maintenance pending suit.
Now this is a tricky one as you say your stbx is on here too .. but it may just make sense for you to both to share some financial details re assets, income etc .. and allow the good folk at wiki to see if they can help you to reach a sensible agreement ... we don't want to get caught in any flak :blink: but if you think it would help then feel free.
You never know, it could make a big difference to all of you

.
Hadenoughnow
Matrimonial Causes Act 1973 chapter 18 section 25 thus:-
25.-—(l) It shall be the duty of the court in deciding whether to exercise its powers under section 23(l)(a)(b) or (Cl or 24 above in relation to a party to the marriage and, if so, in what manner, to have regard to all the circumstances of the case including the following matters, that is to say—
(a) the income, earning capacity, property and other financial resources which each of the parties to the marriage has or is likely to have in the foreseeable future;
(b) the financial needs, obligations and responsibilities
which each of the parties to the marriage has or is
likely to have in the foreseeable future;
(c) the standard of living enjoyed by the family before the breakdown of the marriage;
(d) the age of each party to the marriage and the duration of the marriage;
(e) any physical or mental disability of either of the parties to the marriage;
(f) the contributions made by each of the parties to the
welfare of the family, including any contribution made
by looking after the home or caring for the family;
(g) in the case of proceedings for divorce or nullity of marriage,the value to either of the parties to the marriage of any benefit (for example, a pension) which, by reason of the dissolution or annulment of the marriage, that party will lose the chance of acquiring;
and so to exercise those powers as to place the parties, so far as it is practicable and, having regard to their conduct, just to do so, in the financial position in which they would have been if the marriage had not broken down and each had properly discharged his or her financial obligations and responsibilities towards the other.