My name is on the mortgage so that is classed as half mine
A mortgage is a liability (ie an obligation to pay a debt) not an asset. The house (or at least the equity in it) is the asset. I assume you are joint owners of the house (ie registered as such at the Land Registry)? However you should also check whether you are registered as 'joint tenants’ or ‘tenants in common’. If tenants in common the property won't automatically go to the other owner if one owner dies.
The government has useful guidance here: www.gov.uk/joint-property-ownership
If you are planning on staying unmarried for the foreseeable future, I would make an appointment with a family solicitor to understand your rights and how you can protect yourself in the event of a split / the death of your partner. To be honest it would probably be cheaper just to go to the registry office and get married though!
I have no savings, the only cash I have access to is what OH gives me and the £80 whatever a month child benefit
In this case I would most definitely get a job. Even if it is just part time, a few hours in an evening or weekend when your partner can look after your son would be a good start. And I would start putting some money into a personal savings account (ie that only you can access).
I'm happily married, but I have a savings account (in my sole name) with enough money that, in the event of an emergency, I could afford to leave DH and set myself up in a new home. I'd recommend every woman (and man) thinks very seriously about doing this. Obviously I'm hoping I never have to leave, but I think it's sensible to put yourself in a position where you are not 100% financially dependent on someone else. I have a friend who had to leave her DH very suddenly when she caught him with another woman, and she was lucky to have enough cash for a flight back to the UK (they were expats living abroad).
You need to look into the possibility of contributing to a pension plan in your name. Even though you are not working, it should be possible to still make contributions into a plan in your name.
I spoke to him about bringing the wedding forward and these reasons and as expected I got “you saying we should get married so you are entitled to more
It's not so you are entitled to "more", it's just to ensure that you - and your child - are protected as well as possible in the event that something unexpected happens.
This explains the differences between marriage and living together as a couple. I think everyone in a long term relationship (especially with kids) should read it:
www.citizensadvice.org.uk/family/living-together-marriage-and-civil-partnership/living-together-and-marriage-legal-differences/#h-children
Hopefully you and your DP will live long and happy lives together. I hope the same for me and my DH. However, I have seen friends' relationships break down completely out of the blue, and I know of more than one person who has had their partner die in their 30s, so my personal philosophy is to make sure I am as well prepared as possible, to make my life easier if anything bad were to happen.