PUVA nail psoriasis - scared

My PUVA treatment starts this week but I’m terrified of the side effects. My nail psoriasis (all my finger nails and toe nails on one foot) are badly affected by nail psoriasis. Some nails are badly misshapen and all of them have fallen off at some point and don’t grow back properly. Skin below nails is inflamed for some of my fingers. I currently have 4 finger nails that have come off. My toe nails have subungual keratosis. Topical solutions have not worked. My nails need sorting but the prospect of PUVA terrifies me. Has anyone tried PUVA for severe nail psoriasis? Is UVB better? Or any other treatments? I’m in England.