Good effort. this will be the shead for the next propper build. You can't expect to do it rigth the first time. Some inspiration for you.
https://www.youtube.com/watch?v=BBX5qh09OIE&t=6762sDo you intend to cover the outer walls with plank clapboards? Also insulation between the logs is an idea, lots of farmhouses here in Norway from 1700 to mid 1900 used newspaper for some extra insulation between the log wall and the clapboard on the inside, mainly to stop drafts.