Here is some advice I gave to a songwriting student – who already has stories to tell but finds it difficult to write lyrics, If you are in the same situation you might find this useful.
Regarding lyrics. In your situation – as someone who already has things to say – my suggestion would be to write the story of a song in prose first (no need to edit and polish it). Put it down on paper (metaphorically speaking – as you may use a computer) – then review it to ensure there is a clear beginning, middle, and end – and a clear point/message/lesson.
The point/message/lesson is your chorus – the beginning, middle and end parts are your verses. Set out a standard song structure in your DAW (digital audio workstation) if you use one – and start working on each section – by singing the message that is in each section of your story.
Don’t worry if it is not coming together right away or if it doesn’t rhyme or if it doesn’t make sense – just keep singing it over and over again – and recording as you go. This might take a while – but your brain is a massive computer and your subconscious is a magic universe of ideas – so when you get into the right mind-state – the words wills start to organise themselves – as if by magic.
As they are organising themselves – write them down – and keep writing and re-writing as they come together. You’ll have songs of your own to sing in no time. You have the songs in you and you already have all the talent you need. What you are doing now is learning the craft – mainly by letting go off the idea that you can’t do it.
It’s not your conscious mind that does the real work – it’s your subconscious mind – and that’s not something you need to worry about trying to control – that’s the magical part. If you don’t have a DAW – do it into your phone.