Sunken homemade bread

[Guest guest]

I am kinda new to making my own bread and while it is going okay I am

having trouble with a few things. First, after I take my bread out

of the oven it looks fine but after it cools the center has

completely sunken in. This makes it hard to maintain nice large

slices suitable for sandwiches. I then further contribute to

the " smushed in " bread when I slice it as it seems to smoosh when I

slice it (I bought one of those slicing guides, but wonder if I

should invest in an electric knife?). Any ideas thankfully welcome.

-Meggie