So the days pass and I still desperately strain for hope of deliverance. When will what little talent I had to create things of interest please return to me? Instead I labour for days and nothing seems to work. I no longer have the motivation to get out to capture life with my camera; My art is showing terminal signs of decay and decline and all I seem to find interest in is my historical research which is very rewarding but I all the time feel that I have missed one huge well known fact that renders everything I have discovered out moot,
I guess the only way out of this funk is to just keep working at things in the vain hope that enthusiasm will return and this unblock the drain. It is, at least, a hope.
Oh hippopotamus
Simon's Blog 
Many people complain of creative block. Some make things far worse by struggling in vain to overcome it. So if cartoons/caricatures elude you and photographic opportunities seem unavailable (it is a grey winter after all) then perhaps you need to court a different muse.
You may, or may not, need new software, but as a suggestion if you take your favourite pictures and transform them using your sketching abilities into something completely new then you may start your creative juices going again. Perhaps several photos of the same thing transformed into a triptych? Or possibly a chain of sketches joined into a cartoon strip?
You may find that thinking about what you could do is more helpful than thinking about what you can’t do.