Blues improv, licks and expressing yourself through improv.
Some thoughts.
You need a guitar vocabulary made of words, phrases, sentences etc. Then you can express yourself and make up conversations. Maybe even just with yourself!
This vocabulary begins with learning and using scale pattern fragments and licks etc.
Playing the scales is one thing. And you must practice them around and around, over and over, preferably to a metronome or click track at differing speeds. Alternate picking. But using them purposefully is crucial to instilling them in your head and fingers. Give yourself the facility to play from the notes / patterns of a scale at will, really learn it ... 3-in-a-line, 4-in-a-line, random change of direction, string skipping etc etc etc.
Learn licks, one at a time to begin. For each new lick, play it over and over forwards, backwards, broken down into fragments and reconstituted .... and improvised over loads of backing tracks too. You have to work with these licks, really work them. Honestly and truly, you have to play one lick over a full 3-4 minute backing track and really listen how it works over the chord changes. Then start messing with it, to do something different, putting your own spin on it. That is the key to improvising. As you spend time - hours and more - just fiddling around with licks to play them as taught, to deconstruct them and play them as fragments, you will automatically find yourself playing new licks that you create by putting the fragments back together in different order, or extending by adding extra flourishes at the end or additional notes at the outset.
Listen carefully to the licks you play.
As you play them slow, fast, smoothly or in broken staccato jumps ... can you imagine singing them? If so, what words are you singing? What lyrics can you think? What feeling are you conveying? What emotions are you drawing on? Do you need to repeat it - like a plaintive cry of blues? I'm all out of love and my baby's gone ... I said I'm all out of love and my baby's gone ... She's gone, gone and I won't see her no more ... etc.
Hopefully you get the idea.
Think too that if you were to sing that you would need to breathe. Blues lead playing, licks, runs, phrases, improv, soling ... it needs to breathe too. It needs space between the phrases. Some phrases need to be shouted, others whispered. Some come out in a rush. Some as a long, slow drawl. Speak through your fingers. Make yourself feel it by imagining it and inhabiting the blues space.