Sleep regression or something else?

Sa

LO aggressively fights going to sleep for both naps and bedtime. This is not really a new thing as she's been a bad sleeper her whole life but the last few nights she has been waking up every 1.5-2 hours and crying or screaming. She has been sick with a virus-fever and congestion so we thought that was the problem but she is better now and we're still dealing with the poor sleep. Is it normal for them to wake up crying/screaming if it's a sleep regression or is something else going on here?

Edited to add age...4 months/19 weeks on Thursday