Custom made door threshold & small jobs

Hi, We have a tricky threshold/"list" between the living room and bedroom, where the floor in one of the rooms is about 1-2mm taller than the other. It is quite an awkward shape and we have to be mindful of the door. i have made several attempts at making one myself but i am not skilled enough to get it to fit. We really need an expert to take a look and try to make something that fits. There are also some additional `small` jobs that could be looked at around the apartment as well.