I didn't calculate depreciation into my taxes for 2017 and 2018. I will send in an amendment with a CPA. Can I receive an estimate of how much I'll likely get back?

If you are having a CPA  completing the amended returns then ask them for that amount as no one here has access to your personal info to give you any kind of answer. 

TUrbotax does not do your taxes for you, not even estimates.