Contacts lost after deleting email account

Ive had my work email account on my phone for about 6 years, and apparently all the contacts i have added since then were tied to that account. I recently left changed positions within that company, and so their tech desk told me to delete the email account and re-add it. Well, when I deleted it, half of the contacts in my messages changed to just phone numbers (no names) and contacts are there, but their phone numbers are now gone. How can i get these back? I believe I have icloud as a backup, but is there a way to restore? Im not sure if i regularly backup, or if it does it automatically?