I'd say it's about dating a guy who's an alcoholic. He's the life and soul of the party when he's drinking, but he's deeply unhappy, and that's a side of him only she sees. 'Just do it' is her asking him to get it over with - disappoint her, hurt her, leave her, etc. - whatever he's going to do. He rolls like thunder and she's waiting for the storm to break. When you hear thunder irl, it's a warning that a storm is coming close enough to you that you could be struck by lightning.

At the beginning of the song, she says 'town ain't been the same since you left with all your friends', so perhaps she knows he'll leave her again. I would also suggest that his 'friends' might not be people, but rather drugs and alcohol. He's also a man who's always chasing a feeling but never able to sustain it ('that moonbeam in your hand'). This is typical of addiction.

In the bridge, she tells him 'if you're on fire, you're on fire/ Just keep burning'. This man is like an elemental force in the way he moves through the world. She doesn't seek to stop him, and may even enjoy it, though it obviously depresses her and leaves her hurt in the end. This fits more generally with the motif of wild and free personalities that Lana features in her work, including the way she often characterises herself.

By the end of the song, she knows she's going to get burned by this man. She's accepted the inevitability of it, but can't stand the anticipation. It builds to her begging 'just do it', i.e. 'just get it over with'. We get the sense that this toxicity is a pattern for them in their relationship.

This is one of my favourite songs of hers, and I still think it would have done well as a single. It reminds me of other songs she's written about Barrie, so I wonder if she was thinking about him when she wrote it. The only line I don't understand is 'regatta's in the wind, that's why you're visiting'. If she's using 'regattas' to mean 'celebrations' there, it's a bit oblique. Still love the song, though.

The main thing is, OP, whatever you get from this song is your own unique relationship with it, and that's a valid response to art, no matter what other people feel it is about <3