Designer crashes on open

[NaomiS]

I cannot open my work. Each time I try designer crashes. The file size is 43MB and I am using an iPad Pro with lots of storage remaining. Is this a high file size? I am only drawing using my Apple Pencil and am zooming in to the maximum amount to get the detail. Why has the file reached such a high amount? I have not copied and pasted only drawn. But I have been adding and adding for 2 months working on this project now. Is there another way to access my work and from there a way to reduce the file size somehow so this doesn’t happen? It is very frustrating as I can’t get into my work. How should I be working when I am drawing in the app. Is there a better way to be doing this? I’ve had my work crash before now and I don’t understand why the app isn’t powerful enough to cope with this. Previous work I had copied a d pasted so had embedded work but this work is literally just layers and layers of drawing using Apple Pencil. Anyone solve this??  I’m so upset to not be able to finish my work. 

[DM1]

7 hours ago, NaomiS said:

How should I be working when I am drawing in the app. Is there a better way to be doing this?

Are you 'Saving' your work or simply relying on the app’s sandbox version. If the latter, that is a very poor work practice (sorry, but true).
To save your file  (ie. create a .afdesign file that can be copied/moved/backed up), you need to tap Save in the Home screens 3bar menu (under the files Home Screen image) When saved this way you will have an accessible file created in the default save location (Designer folder on iPad or iCloud). This also creates a Save option in the Workscreen Document menu.
The sandbox version is virtually inaccessible to any other app and cannot be backed up. If it glitches you are generally unable to recover it. (Mods may be able to offer suggestions).Sometimes creating a copy using Home Screen 3bar menu provides another sandbox file that 'MAY' open. If not you may have to start again😩

For the future, Create your file and immediately SAVE it. Now your edits will update a real file. Back the file up regularly and if the working copy is ever corrupted, you should have a recent backup to revert to.