Seekers as a different species of Cybertronians had their own rules in raising sparklings and sadly one of this rules been this:

Seeker quickly leave their sparkling after a month of raising it if now even a shorter time.

Yes. It was hurting and sad but that's nature.

Starscream: "You would survive...I...I know it..."

Your sire says quietly, putting you down. You were just on your first fly , It's was exciting and interesting but you'd never expect your sire to leave you right after this happy moment. But here you are...

Starscream: "You're a big Bot now...."

He says , stepping away from you.