There's a way, by editing your save. You run on Android if I remember well? On Ios that wouldn't work.
You have to go into your saves folder. Your game state is saved in the Persistant.qks file. The subfolder Quicksaves contains all your saves.
Choose the save you want to edit (it will probably be the persistant),
make a backup, and rename it with a .txt extension. Then you can open it with a text file.
All your vessels are listed in this file:
Each vessel is located thanks to its adress (the Sun in this case), which means that it's in the SOI of said body, and its global position coordinates x and y, in meters (z is always 0 since it's a 2D game).
You can simply search the word "globalPosition" to iterate through all of them.
The vessels you want to delete are the one which adress is "Sun", and which coordinates are huge. 15570000000 is at Jupiter level, so all objects that are way further than that probably need to be deleted.
Good luck
(Beaten by the Lieutenant!)