Venlafaxine :: No Better Effects After 3 Weeks

I've had social anxiety / gad since highschool and I am now 25. I first took citalopram at 17 and took most other ssris trying to find one which helped, it was only when I took sertraline at around age 21 that I really felt benefit from a med, I noticed a feeling of content I'd not experienced since my childhood days, and soon got a job and began to socialise a bit after years of being a recluse. Anyway, the good feelings only lasted a year and I found myself asking for meds again, so my doctor put me on cymbalta which I took for 6 weeks and felt no benefit. I then went back and was put back on escitalopram which I felt had been somewhat helpful and I stayed on that for a couple of years.

Again I found myself suffering anxiety on a daily basis, so I needed a new med, so I went to my doctor again and was put on venlafaxine in late 2014 at a starting dose of 37.5 twice a day. I took my first and felt completely out of it and suffered worse panic attacks at work, so I tried to come of meds altogether but found myself taking half a tablet every other day to prevent the horrible withdrawals, when I completely stopped I felt more anxious and depressed so went back to my GP who recommended mirtazapine which I refused, I explained I didn't want to keep taking more meds for them not to work, as I didn't want to end up on last resort meds such as MAOI's when I am not clinically depressed or a risk per se. So i agreed to give Venlafaxine a try at 75mg a day and go back in a few weeks.

I am now on week 3 of venlafaxine and the positives are decreased anxiety at 'work', although this med makes me so tired I have no energy to be anxious, and a feeling of content, although I could sit in all day and not feel compelled to do anything as I feel 'ok' if that makes sense, which is a bad thing really. The negatives are a feeling of emotional numbness, no desire or motivation to achieve goals, tiredness all the time and no desire to socialise which suggests no improvement in social anxiety, and teeth clenching which happens with all meds for me.

So my question is should I keep taking venlafaxine, should I go back on sertraline in the hope it might work like the first time, or should I go on mirtazapine even though I don't want to feel even more zombiefied and don't want to feel hungry all the time. Or should I stop meds?