This expression means that it is not easy, that it is complicated. "Tá" is a informal abbreviation for the correct verb conjugation "está", and "foda" could be translated to hard, or fucked.
Used to describe that something is not easy. It could be a relationship, your job, the car maintenance, etc.
- Como vai a vida Seu João?
- Tá foda. Não pára de aparecer problema.