RE: Lost deer....Big learning experience (long)
Your deer lived - and is not likely going to die as a result of the wound (infection, predators are its enemies now).
You did well in following up - better than most by far.
Mistakes happen - not all bow hits are kills - in fact its more like 40%.
Learn from your experience - and move forward - as much as people do not want to admit it - you' ll be a better hunter as a result.