Thanks, MM. 
You do wonderful graphics (mutual admiration society) and I’m surprised you don’t have Photoshop.
Since I am the cheapest of the broke, and largely self-taught, may I suggest you do what I’ve done? Go to Ebay, find a very experienced seller (one of those with a 99% rating and hundreds of stuff to sell) and find a Buy It Now old Photoshop program. Like version 6 or CS. (I got 6 from a friend.) You can probably get it for around $50 and it will ship to you. Next month the schools will all be back and they snap them up from students who are unloading older software and getting new stuff for classes. Anyway, that and a dummies book will have you playing in no time. Save any work you do to a copy in a jpg, low to medium res. for posting here. With graphic skills already in place like you have, it’s just a matter of learning which way it’s done in their program, but they’re all compatible and basically operate the same way. A nice little project for the coming winter for you. I expect to see major greatness by spring. 