Thoughts? could really bad headaches cause temporary memory loss?

Underlying condition: There is probably no causal relationship but it is important to ensure that they are not both part of the same underlying condition. For example migraines can - if affecting certain intracranial vessels - cause memory loss along with the headaches. There are some other less likely conditions e.g. A tumor that could explain this but a more detailed examination by your doctor will clear things up.

Perhaps: Some patients with complex or classical migraine episodes may have a transient challenge with "dysphrenia hemicrania transitoria", fully reversible but lasting on occasion up to 30-40 minutes. Some others may find the pain so intense that it is indeed distracting, preventing focus and concentration. If this is you, get onto a preventative and feel better.