Will I get the stimulus check if I accidentally clicked can be claimed as dependent?

probably not - 

but the worst case is that you can

either amend (at least a 16 week wait with no guarantee that the IRS will immediately pay out the stimulus - maybe they will and maybe they won't - they have provided no guidance. 

or wait and pick up the stimulus on your 2020 tax return. 

• The stimulus payments are really based on your 2020 tax return (income, dependents, etc).
• The IRS is using either 2018 or 2019 – whatever is available  - to ESTIMATE that payment
• When you file next year there will be a “settle up” section on the tax return. 
• If you are due more stimulus (and this would include where you simply never received it), you will receive it through the 2020 tax filing as an additional refund

If you received too much stimulus (not the issue here), by law , you are not required to return it