I would accept that all the equity in the house is yours (as it is now), although obviously being together, we would share that money, spending it in later life.
However, in being the named person on the mortgage, there would have to be certain safe guards for me, re not getting a bad credit record should things go pear-shaped and the property have to be sold, to protect me. In time, I would expect you to be able to once again take over the mortgage – once your bad credit rating was history.