Were you married in 2019? Why didn't you file a Joint return? Did your spouse file Married filing Separate or Joint or ? Are you filing Joint for 2020? How much Stimulus payments did they get? Did they claim any dependents for 2019 or 2020?
Then yes you should be able to get both the stimulus amounts on your Joint 2020 return. When you get to the Stimulus screens say No you didn't get the amounts listed. Then 2 boxes will open up. Enter the amounts your spouse got. And you should qualify for your missing 1200+600 = 1800 on 1040 line 30 for the Recovery Rebate Credit. Even if the parents got it for you. You can get your own now.