What affect sex?

My bf and I are in a relationship for nearly 2 years and we don’t live together. Recently we haven’t had sex for 5-7 months now (2 months because of quarantine so that doesn’t count right?) This is so not the same situation for us at the beginning of the relationship.

Could stress from work and money can affect his desire? He never askes for it anymore idk why... or is there any other common reasons apart from the satisfaction during our intimacy?

what can I do to fix this situation?

I am trying to understand everything because this is my first serious relationship that involves sex