i have a "tons" plugins-effects-vsti... and i can not make anything interesting, at least it sounds ok. I have an incredible inner need to express myself through music. result (mostly at the end is frustration. 
there was time i wanted to try out and use every single one of the dozens plug-ins that are out there. turned out i was just scrolling through the list and never completed anything or the output was spasmodic rubbish. so i removed all the plugs, zipped them and stored on a backup drive. was truly liberating act. now i pick one every once i a while and build a project around it. take time, explore, see if it'll be of any use for me. than it might make the list, which is limited to two plugs at the moment. thus can focus on working on the track and not pondering which of my many great plugs i could/should/would/might/am to use.
it was mentioned a few times on the forum and it looks like it comes up again. not saying it's your case but abundance of gear/soft might negatively influence your creativity and causes frustration. cross the stream where it's the shallowest...(and dump the heavy load before you enter it)
yet i'm glad that this thread developed and places like
www.kvraudio.com exist. it's great to see so many people coming with so many ideas for plugs. some of them really well done with spectacular possibilities.
how much time you need for only one track?
sometimes an hour sometimes a month or more.
do you processing every instrument?
to process or not to process. that is the question

again, no principle here for me. our projects usually involve a few instruments. not all of them are processed. but than, the end signal might get heavily processed. there are so many scenarios possible. i guess in case you have a solid number of instruments, processing all them and still keeping a nice, clean mix is a challenge. an approach to use less instruments and diversify their output, tinker with them, create room for play and possibility to model the instrument during a live performance proved better for us than amassing an armada of instruments and engineer them into a track. the latter it's certainly achievable, yet requires likely years of experience and talent and skills. and time i guess. wish i could do that. hopeful it'll come with practice.