Rebirth of Martial Arts in Another World

Reborn in another world, with martial arts as his esteem, from a young man who devoted himself to martial arts to a general guarding the country's borders, from his lover before time travel to being unable to stay together in this life, from fighting against thousands of martial arts armies, to retreating into the mountains just for the protection of that one person, even if his martial arts skills are great, he can't beat the laxity in his heart.