I noticed that at days after a night of poor sleep my ocd & anxiety get worse, and vice versa. could poor sleep possibly cause my anxiety and ocd?

Not causative: Poor sleep can exacerbate or worsen anxiety and ocd -- but it does not directly cause them. Poor sleep may even be part of these conditions.

No but...: Poor sleep doesn't cause ocd and anxiety, but lack of sleep or poor sleep can certainly make your anxiety and ocd symptoms worse, and regular sleep ~8 hours can go a long way to help anxiety and ocd symptoms.