Disrupted. Now what?

I disrupted our 17 yo FS placement a few weeks ago for several reasons. This kid ran away for a week at a time 3 or 4 times. He totally gave up on school and refused to make different choices.

At first I felt really guilty and like a failure, but there was truly nothing we could do for this kid and it was costing our mental health. Now I'm in more relief, but feeling guilty over the relief! He was with us for 7 months and he totally trashed the room we put lots of love and care in (to the point we had to throw away almost everything) and I'm still randomly finding knives he stashed. He wasn't doing it intentionally, just never learned better.

All this to say, we might be done fostering. We were just licensed about a year ago and this was our second placement. I've been told we just got tough placements but I fear that if all kids are like this, we are not equipped. We built a lovely relationship and connection with these kids but... is that really enough? Feels like we didn't really help them and I thought that was the whole point.

If you disrupted, did you feel like this after? Did you eventually foster again? Not sure if i should think about being a mentor or something instead.