I think my milk is drying up

C

My son is 19 weeks and I’ve been exclusively breastfeeding since he was born. I’ve had to pump during the work day now that I’m back full time and have noticed a decrease in my supply over the course of the last few days. I’ve been sick so thought my decrease was due to my illness but now that I’m better, I haven’t seen an increase 😢

For those of you who have had your milk dry up, what was your experience? How did you know it was happening? Are you supplementing now?