It is very easy to get circeled and die fast but I asure you the game is beatable in the current form.
I havn't checked your recording yet but from what you write it sounds like you get circled by the enemies a lot.
Try to use the level to your advantage. Try to use doors and corridors for ground control and attack enemies diagonal whenever possible. The undead can attack diagonal too but they really prefere not to. Don't run into groups of enemies. Let them come and avoid battles in big, empty rooms.