Write me a contract

Hi, Me and my boyfriend are moving in together and we would like to both have some 'security' in this as it is only a single tenant contract. We were looking at a contract to cover this, we are in England and we want a contract covering the following terms: Guarantee/ contingency if break up. Stay living together until the end of that terms rent or they find a new place to live If damage is neithers fault we both pay. (Wear and tear) If damage is particulars friend we take responsibility for our friends damage and pay. (Unless it's others fault as to why friend made damage.) Both pay half the rent. (Including deposit and tenancy fee). The party who doesn't pay their half is liable. Always make the other person aware before bringing anyone over to the flat this includes flat parties which require agreement from both people. If any friends want to stay over for the night this also requires both people's permission. During any arguments the party who wants to cool down will be the one to leave the flat if required and the other person will not stop them. Any mess created will be tidied by the person who created the mess at the earliest available opportunity. Space to display and store is halved, an exception is created where there may be 3 shelves where one is for no particular person and is more of a household storage. When the deposit is returned it will be distributed proportionately to damage done by a person, or anything else relevant.