i know what you're talking about i myself never took lessons (which i regret very badly) i had the same problem.
what i did was taking the chords i want to build the solo on holding them and listening to every note then found those notes anywhere else on the board
then just playing them adding slides between them or vibrato or just hammer-on/pull-offs whenever i felt like it.
i started just jaming like this finding more matchable notes adding "spirit" to it
after the whole process i write down part by part the thing and play it
if i like it i keep it if i dont i throw it
after writing many you develope your own style and you find it easier to write

ps i will that lessons soon just to see how its like...