Damp, mold and condensation

Hi, I wondered if you might help. I have damp patches located around upvc windows and doors in my home. They are located on the south side of the house and are exposed to high winds and surface rain. I have been getting black mold on the walls around the upvc double Doors down stairs and a staining damp patch under the window sill upstairs. The damp patch upstairs is 1 foot width. I want to summarize some of my issues below to keep it short and concise and to see what might be the problem and how to fix it Downstairs : 1)There is a decking outside. The post is pinned to the wall on the exterior opposite where I get mold on the interior 2) the cold and mold wall happens just above the skirting near where wall meets upvc double doors 3) there is a draft in the middle of the doors above where the handles are.... I can feel draft coming in 4) the Mortor around the area has little cracks in parts on exterior wall 5) i get a damp sill and upvc door downstairs at the double doors on the left side fitting with where the mold develops on the 90 degree turn of the wall 6) there is a TV stand a bit further back where air flow may be not helping but it's not in front of the mold and cold wall Upstairs: 1) Pretty much vertical above the downstairs stairs patch... Roof has not been replaced in a while.... Covered in moss and some copping broken off at top.... There is no water running down wall outside 2) stained below corner of window sill. 3) cracked Mortor joints on exterior 4) again gets battered by wind and elements 5) draft behind plastic window fascia I have removed at top corner of window above damp patch. 6) there is a lip under the exterior window sill to stop water falling back to the wall Both areas are very cold to touch. Downstairs has black mold and upstairs has a damp patch. Again common things are they happen by the windows and where drafts are. Damp course appears to be in place I want to know what the problem is and what the best approach is to fix it? Tha kyou. I have used a meter and it tells me that there does not seem to be a void. It's getting in somewhere but where? Thankyou