I feel like a failure

I’m an intern and I feel like a failure. I have a client that’s been a no show for 2 weeks and when I called their number to reach out, it was disconnected. There was one session where they mentioned passive SI and though I risk assessed, asked about frequency, triggers, intensity, and what they can do when they have those thoughts, I completely forgot to do a safety plan. I risk assessed the week after and they were no longer experiencing SI. There was no mention of it in the sessions following. However, this ct does have a habit of undoing. Our last session was sorta intense and there was a lot of challenging and resistance. They haven’t been back since. I’ve emailed them 3 times and if they’re a no show again, I will have to terminate. I feel horrible and hope they’re okay. I wish I’ve done so many things differently. I really want to be a better therapist.