Here and Now and Then by Mike Chen

Time travel that hits a snag. Kin is a secret agent who goes to the past to hunt down bad guys until something goes wrong and he gets stuck. He makes the best of it - starts a new career, falls in love and has a child. Life is good until the future comes back for him. There are rules to prevent complications and it will mean erasing Kin's involvement in the past - everything and his daughter. Even though Kin was happy in his future life before he got stuck, it is still a big adjustment coming back and he can't face the idea of failing his daughter back in the past. Against the laws and what is best for his safety, Kin must find a way to get back to the past and save his daughter. Warning - the ending will have you diving for the tissue box. This is a feel-good time travel book with a big-hearted hero just trying to do right by everyone.