What's everyone's experiences with sertraline for anxiety?

I took it in the past for 18month for dizziness, i wasnt anxious at that time as i am now. Now i have severe anxiety and daily panic attacks.

When i took sertraline in the past it was amazing. I felt great. It took two weeks to kick in and the only side effects i had was diarrhea and headaches which passed quickly.

I felt like my mind didn't get stuck in loops constantly obsessing about things and i could actually live my life. My dizziness got much better as i wasnt thinking about it so much. I weaned off and felt pretty good for about a year.

Fast forward to now and my anxiety is so bad, i have tried twice to get back on sertraline, even starting at 25mg doses.

I cannot tolerate it at all. I have even worse anxiety. Was waking up through the night with multiple panic attacks, aching jaw, bad insomnia where I was only getting 3 hours of sleep at night. My anxiety was through the roof! Unbareable. 

I stopped after 6 days as i had to have time off work i was so bad and ive never done that before! I felt really low coming off it too. 

Why am iso bad on it this time? I never had these side effects before. I found them really stimulating this time where as the first time i was yawning all the time and was getting plenty of sleep on them.