The Helicoil coming out with the bolt is usually an indication that the hole was drilled out too large. It takes a great deal of skill to accurately drill out a hole with a hand drill with the head installed. Ideally it would be done with the head off on a drill press but that is a great deal of work.
You could try a longer Helicoil that would have more grabbing surface with the head.

Even with those 2 bolts not tightening fully you should not have the large amount of oil leaking that is shown in your pictures on another post. Maybe you should start over and pressure wash and degrease the engine and try to track down the source.

I thought you were taking it to a mechanic on the 15th.

Edit: I just saw your other thread where you explained why you did not take it to the mechanic.