Hm, I also find it very difficult honestly. Do you know how much light you have in the garden/behind the house? We have almost completely north at the back and there is sun in the garden all day. The house itself only casts a shadow about three meters into the garden and the rest is sun... In the east, on the other hand, we really only have a few hours of sun in the morning, but we also have a house directly adjacent there... Hm, I don’t know... If I were you, I might try to make the house even narrower and longer so that it opens more towards the southwest. Above all, I would probably place the garage on the right side of the house, I think. Our kitchen is also northwest and bright, whereas the storage room is northeast and is quite dark...
And the idea of having the entrance from the side I also find to be a very good option, honestly. If a double garage is possible, then you should be able to make it smaller and plan the entrance between the garage and the house???
Then I would place the living room completely in the southwest at the front and the kitchen in the back right in the southeast corner, and the northeast corner at the back left would then, as usual, have the cloakroom, stairs, and guest WC.