Struggling with Depression and PMDD

I’ve been so depressive the last couple of months. I’ve been taking Zoloft for PMDD, depression, and anxiety since about last November-ish. I think it’s been wearing off. I’ve been consistently tired, depressed, and unmotivated for about 3-4 months. I’ll go into spurts of productivity but that’s not often. Has this happened to anyone else too? I feel alone with the way I feel and think. I feel like I’ll never be healed from my PMDD and depressive symptoms. Also, my pet just died last week and it hasn’t been helping with overthinking every day missing her.