Stuck in a total creative rut right now

Things haven’t been going well for me in a creative sense lately. I don’t know what it is, but I haven’t been able to hand sketch a decent car for about the past three weeks. Seriously – it’s frustrating. I have been really busy on some other projects lately, so I think my brain is just tired or something – but wow. Attached are some very weak attempts at trying to get a decent sketch going.

I think what I’m going to try and do is get back to my “10 minutes a day” sketch routine. I just need to get back into the groove of things, and not try to put so much effort into creating a finished rendering. Just ten minutes a day, just to make sure I don’t forget how to draw!