You should avoid seeing other people when you're not feeling well.
When you're feeling a little run-down, it's better not to be around other people.
ーYou should avoid seeing other people when you're not feeling well.
「体調が悪い時は、人と会うのを控えたほうが良い」
to avoid seeing other people で「人に会うのを控える」
when you're not feeling well で「あなたが体調が悪い時」
ーWhen you're feeling a little run-down, it's better not to be around other people.
「疲れている時、他の人の周りにいないほうが良い」
to feel run-down で「疲労感がある・疲れ果てる」
it's better not to ... で「…しないほうが良い」
ご参考まで!