Mirtazapine and Sertraline - please help

I’m really at a low point and feeling pretty hopeless. I have been on Sertraline for nearly 4 years and my doctor added 15mg Mirtazapine in June 2017. I cut this down to 7.5 after a few months.

In mid January this year I started having anxiety issues again so went back on 15mg mirtazapine along with 150 Sertraline. Felt ok after a week or so, then another crash and the sertraline was put up to 200. Two weeks later the Mirtazapine went up to 30.

All together I have been on 200mg sertraline for 6 weeks and 30mg Mirtazapine for 4 weeks but my anxiety is still all over the place, feel ok for a day or two then crash again. I’m feeling like this will never end. Still waiting for my local mental health team to get in touch and I’m just getting desperate now, so scared I won’t get better.

please, can anyone put my mind at rest? Do I just need to give it a while longer?

At that dose of each you have loads of serotonin flying about making you tense. 15 of mirtazipine is the top anxiolytic dose.
Have you been diagnosed with GAD? You don’t want the Valium route but has he discussed pregabalin? Avoid quetiapine if offered in my humble opinion.
Just a thought.
I could not tolerate the doses you are on and never gave that much when I was a Gp.
Regards Dick