AITAH for being upset that my boyfriend missed his job's orientation twice?

My boyfriend [28m] and I [28m] have been dating for a year. Out of the year, he has been unemployed for 8 months.

It was a very stressful time for us, and my boyfriend was struggling for months to find a job. I told my mother about our struggles and she found him a weekend job at her workplace (where she's been for 35 years and is set to retire at the end of this month).

My boyfriend interviewed and got the job. It wasn't the type of job he wanted by any means, but it was something. It would allow him to start paying his bills and contributing to the expenses around the house. It also didn't start for another month.

In the month leading up to his start date, he was offered a full-time job elsewhere, and then another! And they were jobs that aligned better with his career goals. This was perfect. He started his full-time job yesterday.

Yesterday he also showed me an email thread with the recruiter at my mother's workplace, where he missed his start date two weeks ago and rescheduled it. Last Friday was his new start date at my mother's workplace. He emailed them yesterday afternoon (Monday -- 3 days later), notifying them that he'd taken another role elsewhere that fits his career better.

Needless to say, I was shocked and embarrassed to hear how he was handling this! My mother (who I barely have a relationship with) went out of her way to us. She spent the last days at her humble job of 35 years advocating for a job for a new boyfriend of mine, who missed his start date twice, and who didn't even have the courtesy to send a timely email to the job to let them know he had found something else.

I am so upset and hurt by this. I told my boyfriend that everyone knows he didn't exactly want the job, but he didn't have to shit on everyone who was helping him the moment he found a better opportunity.

We spoke about it last night and he says he's sorry and doesn't know how he missed those dates. But this time sorry doesn't feel enough. This feels like a huge slap in the face. I haven't spoken to him since last night.

AITAH for being this upset? Or am I being a drama queen about this?