Designing block & maths

I can make and design 2D pretty things, but have a mental block when it comes to 3D.
I need to get over my block!

I have always knitted myself shapeless cake jumpers & cardis, but have never made a garment that anyone else would want to wear.
But now I have turned into a crocheter I have managed to make 3 reasonably sucessful cardis.
But am very anxious about turning them into patterns, you might not like them, they might not make sense
My main problem is the sizing and maths involved.
Oh and the pattern writing - :-)
And so all last week I have been doing crochet maths, it really is basic primary school maths, its driving me mad, I can't even explain to Homer what I am trying to do so its impossible to ask him to help.
I get really frustrated when he doesn't understand my logic, its perfectly logical, maybe a bit warped.
Finally last night I finally managed to solve a couple of my maths problems.
And even better than that worked out a couple of stitch designs that work really well.
Am really smug this morning as I might be overcoming my block at last.
Feeling that maybe I could start to tackle secondry school maths.
Now all I need is the yarn and bionic tester!