Experienced Pilot Advice Needed

I hope this is allowed, but seeking knowledge from experienced commercial pilots or flight attendants.

I travel for work quite a bit so I am very familiar with all that comes with flying commercial - turbulence, weather, etc. I’ve never had flight anxiety, in fact I would say I was unphased by turbulence of any kind. About a year ago a flight changed that outlook and I’ve been experienced significant flight anxiety since. I still travel for work quite a bit so my hope is by getting an explanation, the understanding will alleviate my anxiety.

I was flying to New Orleans and we’d were well into our take-off, likely close to cruising altitude. I felt a bit of turbulence but nothing abnormal. All of a sudden our flight dropped - what felt like a decent distance. The entire plane screamed, someone yelled “are we going down”, I grabbed onto the arm rests. I grabbed my phone to text my family because I wasn’t sure what was happening. It was a very bad feeling because I genuinely thought we were going down for a second. They came over the system and made the announcement to buckle up if anyone has not been prior- not reassuring. A few minutes later we dropped again but a shorter distance - felt minor in comparison. After stabilizing, the rows around me started chatting - one guy said he has traveled for work for 20 years and had never felt that drop before. The remainder of the flight returned to normal, but nobody ever made an announcement or explained what happened. I emailed Delta months later because I kept experiencing anxiety every time I’d fly.

I’d like to move past this and I’m hoping understanding the root cause, if it is common/abnormal will help.