You have had a very short marriage, and you had no children together.
You are younger than your DH so you have a longer time to build your assets, in the context of your eventual split and your life potential after.
The court will look at both your needs, not your wants. They will ensure the split of assets takes account of what you each bought into your short marriage of only 6 years. They will also protect both sides from attempting to clean out the other side of their assets and ensure each is protected. They may well consider his proposal and agree that it's a fair division of the assets you amassed as a couple during the 6 years.
you have the ability to ring fence any assets that you brought into the marriage the same as he can, As you do not have children there will be no need to consider any dependents' needs such as the primary caregiver keeping the marital home for the stability of the children.
you need to seek legal advice and you definitely need to change your attitude to how you are seeing the split of assets. If the marriage was 30 years and you had taken time out of your career to bring up children, then that would be a completely different matter.
You cannot count the time you were living together. The court will only consider the legal status of marriage. What you negotiate financially outside the court process is different. You just have to agree as the two people in the marriage how things will be split. If you can't agree, then you have to each put forward a proposal and the court will rubber-stamp the final decision according to a 'formula' so it is equitable and consistent with each party's circumstances.
That won't buy me anywhere though.
Then you will have to rent using the £50K. The court isn't there to help you buy a house. They are there to ensure you aren't homeless, so they will see your DHs proposal as the solution to that as the money gives you enough to put down a deposit and 3 months' rent. They will look at your employment status and be satisfied that you have earning potential and years into the future to continue to have stable employment to put a roof over your own head.