Apparently I didn't get enough folate aka B9 from my diet. No wonder I was feeling apathetic and sluggish. I had my first blood test in 10 years and everything else was perfect.
So you can get it if you don't eat enough vegetables, whole grains or fortified foods. Well I didn't eat the last one, ate whole grains but apparently all the vegetables I eat on the reg are low on folate. Tomatoes, onions, white cabbage, carrots, potatoes, apples, bananas, plums, most berries, pineapples, just don't have it that much. I should have been eating beets, spinach, proper green salads with lettuce and bell peppers, broccoli, brussels sprouts, cauliflower, citrus fruits, peanuts and apparently industrially produced fortified cereals.
Anyway previously this all was masked by my habit of eating nutritional yeast that has a ton of folate in it, but I didn't bother to buy a new bag half a year ago, started steaming my potatoes instead of vegetables (and didn't get a new steaming tray).
Anyways, don't be like me. Eat beans, nuts, green leafy greens, cruciferous vegetables besides cabbage and nooch. Maybe citrus fruits, kiwis, mangos, pomegranates, fortified corn flakes, dates and pumpkin seeds too