Your question is very confusing and I don't know what you did.
If you are legally married, both you and your spouse must file a tax return using the "married" status. Either you file one return as "married filing jointly" that lists all your combined income, deductions and dependents, or you file two separate returns as "married filing separately" where each spouse lists their individual income and deductions.
Married filing jointly is almost always better, because the tax rates are lower, and some deductions and credits are limited or disallowed for separate filers. You can file a joint return even if one spouse does not have income, and the result is usually better than if the spouse with income files separately and the spouse with no income does not file.
You never claim your spouse as a dependent.
If you claimed your spouse as a dependent, you need to file an amended return. Did your spouse also file a tax return? If not, why not? It will probably be best to amend to a joint return. If you want to keep filing separately, you would need to file an amended return to remove listing your spouse as a dependent.
The amended return will probably not be processed in time to affect any past or new stimulus payments. However, the first stimulus payment is technically an advance payment of a credit that will be recalculated on your 2020 tax return, so if you file correctly for 2020 and qualify for more than you received, the difference should be added to your 2020 refund.
