Alslam alikum The last Ramadan I was upset from big problems that happened to me so I started to get far from Allah ,I didn’t fast even one day Now I regret it I don’t know what to do
Alaikumassalam wa rahmatullah,
Simply repent sincerely, that’s all that you need to do, and try to be better from now on. You can make up for it with voluntary fasts, although there’s a well-supported opinion that intentionally missed prayers and fasts don’t need to be made up. See: Do Muslims need to make up prayers intentionally missed for years?