@AkshayManke
Turning a Text column into a dropdown is one of the easier actions to do in PowerApps forms because they have built in this ability for you. When you use it, it will automatically do all the connection and displaying and re-displaying without you having to do a thing.
To do so, when you add your Text field to your form (and you have to do this before you unlock the datacard - if you've already unlocked it, then delete the field from your form and add it back), you can then choose the Control Type and change it to "Allowed Values".
This will create a new property on your DataCard called AllowedValues. NOW, unlock the datacard so you can edit that.
There, you can put in the formula to pull from your Status lists.
The only caveat (to keep it simple) is to provide the AllowedValues property with a table with a single column called Value.
So, if you want, for example, all the Titles of a list to show in your dropdown, then set the AllowedValues property to: RenameColumns(yourList.Title, "Title", "Value")
If you need to incorporate a Filter, then:
RenameColumns(Filter(yourList, filterCriteriaHere).Title, "Title", "Value")
After that, everything else is done for you. It will show prior values and it will also convert the dropdown to text for submitting the form.
I hope this is helpful for you.
