My buddy Dave went through the exact same thing last year. He was doing these marathon 45 minute sessions every night and wondering why he felt so drained and stopped seeing any point in it. Then his wife told him to just try writing a few quick lines before bed instead of treating it like homework. He cut it down to like 8 minutes and said it was night and day different. The shorter sessions made him actually want to keep doing it instead of dreading it every night. Sometimes less really is more with this kind of stuff lol.