any suggestions welcome

Hi everyone, looking for any suggestions to help my 2.5 year old get over his new fear of 1) going to bed/ sleeping alone and 2) going on walks. Quick backstory: had to take him to emerg 2 weeks ago ( high fever) and it was traumatic and scary for him. Ever since then he starts screaming & crying when we start his bedtime routine and is scared to go to bed on his own. My husband has been having to lay with him until he falls asleep - which is fine, but we want to help him get over being afraid. Prior to this, he would lay quietly in bed on his own until falling asleep. He also loved walks & saying hi to the trees, waving at trucks. Now he wants to be carried the entire block and screams if we pit him down on the sidewalk. We have gone other fun places since emerg (park, swimming lesson, grocery shopping) and he has been fine mostly.

Any tips are appreciated:)