Sertraline and Mirtazipine

Does any one have any advice about how long doseage changes take to settle. Been on Sert 200mg for 16 years but it pooped out and stopped working. GP recommended staying on Sert and adding Mirtazipane as an augmentation strategy.
I've been on the Mirt approx 10 weeks (2 weeks on 15mg, 4 weeks on 30mg, 3 wks on 45mg and now been back on Mirt 30mg as i found 45mg too activating. Anxiety returned again this afternoon and i have had up and down days for last 2 weeks.
Wondering how long to stick out the 30mg before i make a decision to change. I started feeling better at first but seem to be on a downward spiral again. Feeling hopeless and had a few tears yesterday.

I don't think staying on such a high dose of sertraline is doing you much good. Perhaps changing SSRI to an SNRI (eg venlafaxine/duloxetine) or even another SSRI you haven't tried (if any) alongside mirtazapine would be better.

Speak to your GP/doc about this again because I think you've given sertraline/mirtazapine combo long enough now.

Thanks. I went back to GP but they and the local Mental Health Unit have told me to give it another month. My trajectory is up and down but I think very gradual trend upwards which is why they believe I will get remission on this combo.