G'day Mate,
After reading your post, the first thing I noticed was the fact that you are basically a beginner, I'm sorry you damaged your plane, but, the one thing that was not mentioned was the fact that vibration will cause nuts & bolts to come loose, so balance your props, no matter what size they are, I read lots of posts on here about fellas who "never balance a prop" & have supposedly, never had a problem, if you can cut down on vibration, you won't need any sort of locking compound.
And you didn't check over ALL the fasteners on your plane, after the first flight, while everything was still hot, this was mentioned above.
Next you did not have an experienced pilot helping you, by double checking you plane, & standing by during your first flight, most times a calming voice can mean the difference between a crash & an undamaged plane.
But one thing is true, you have learned a valuable lesson, & all the best in the future.