The web is full of advice on the subject (from people who didn't seem to suffer much from writer's block when pontificating about it!). e.g.
https://blog.reedsy.com/writers-block/
This, from Random House publishing, might be worth a look:
https://authornews.penguinrandomhouse.com/10-ways-to-beat-writers-block/
My own hard drive is littered with partly-completed works, which I keep telling myself I'll finish one day. (The children's novel is about 80% complete, whereas the radio play still has a long way to go. The countless poems all just need 'tidying up a bit' - being something of a perfectionist doesn't help much when it comes to trying to overcome writer's block!)
I keep coming across newspaper articles that I wrote many years ago, which prove that I can write well when given a deadline. I sometimes try to work to self-imposed deadlines these days, to simulate writing for the press again, but, alas, I seem to lack the self-discipline to do so!