I need help!! (PS Elements 7.0)

So here's an example:
I'm done working on my design for the night, so I save my work & shut down my computer. When I go back to work on it the next day, and I try to resize, rotate etc. any of the graphics from my kits, it will turn the backgrounds white & they're no longer transparent.
But if I don't close out photoshop & leave my computer on all night (hibernating) I can do whatever with the graphics & it doesn't change anything. Is there a way to turn this off so that my graphics stay transparent?

I just went to print my daughters invites & for some reason the canvas size was WAY too big, well now I have to re-do everything (luckily I save everything!!) on a new canvas, because if I resize or rotate anything, it turns it white.
I'm also making another invitation right now & I don't have time for this BS!!!

I'm totally kicking my own ass for not making sure my canvas was the right size!  

Anyone have any ideas? I'd love to save some time right now so I can go back to working on the other invitation & quit messing with my daughters! but I need to get them printed today... so...  

For your first problem, save it in .png format instead of .jpeg format!

for your second problem, i am sorry, i don't know what to tell you for that one. Maybe try opening it up>cntrl+a(highlight all)>cntrl+c(to copy it all)>open a brand new document> in the new document cntrl+v (to paste in to the new document) and then work from there?

Good luck, hope this was all helpful  

Quoting Life is G♡♡d :" For your first problem, save it in .png format instead of .jpeg format! for your second problem, i am ... [snip!] ... the new document cntrl+v (to paste in to the new document) and then work from there? Good luck, hope this was all helpful  "

I have no problem saving it as a transparent image, I always save them as png, it's while I'm still working on the design and I save in the middle of my work & if I close the program, then go back to it later, and adjust anything it changes the background of just the image I changed to white... so idk...  

make sure when you update any of it and are gonna be done for the night save it as the PSD so it will save it as is so you can continue to work on it. and you can always change the canvas size you just have to resize the images or you can adjust the whole image size...hope that is what your talking about