Multi-Workspaced UI

So I'm developing a word processor app in that also includes drawing tools. Nothing really crazy, just some simple vector drawing capabilities like node editing and layering. The problem I'm running into is that word processing tools and drawing tools call for very different workspaces and I'm not sure how to implement a switch for this. I'm developing on macOS.

The two modes have equal importance in the flow of this app, and users need to be able to freely swap back and forth between these modes.

So far I have this: and to swap back and forth you click the mode switch button. However, I don't like this. I feel like the button down there just gets in the way.

I figured I could do what Adobe Lightroom does with tabs, something like this: but standard NSTabViews don't work that way, and it makes the window a lot larger for not a lot of functionality. Both of my ideas also look really ugly, at least if I use whats given in Interface Builder.

I guess what's really confusing me is attempting a good looking and functional UI that does my mode switching with standard Interface Builder elements. Any ideas on how to best accomplish my goals?

EDIT: I guess text editing is the primary mode people will be in, but there are some people who absolutely need the vector graphic editing part without having to leave the app, which causes problems for the text they're editing. Images won't ever be raster graphics, it's not precise enough for the diagrams users will be drawing, since the print resolution is very low. And if certain things don't fit on a page, they'd need to be able to switch back real quick to make a change, or to be more precise in positioning of either text or a diagram.

I also want this switch positioned somewhere that makes sense, since the toolbars will change depending on the editing mode the user is in. NSToolbar nowadays is always under the window title, and having an NSTabView underneath it causes a weird disconnect. As far as I know, it's not possible to place an NSTabView above an NSToolbar, not without breaking something at least.

EDIT 2: I just realized, which probably led to confusion and I'm very sorry about that, one image is wrong. It was the first "tabs workspace idea" image (the 3rd overall image) and it included a layers panel which only is supposed to be visible when editing drawings, not with text. Never draw quick images when you're tired I guess. I've replaced it with the correct image.