I promise I won't!

I think it sounds very promising that you have had a response from the brintellix and who knows whether the dose increase has caused more anxiety or whether it's anticipatory anxiety due to uni commitments or whether it would have happened anyway? Therapeutic doses are only therapeutic if they work for the individual..

Don't be pissed off by this because you've had 2 really good weeks and that's success! If you really feel that the 5mg is making you more anxious then you could go back to 2.5 and see if this makes a difference? It may do psychologically because you felt good on this dose previously? Even if it's the placebo effect it doesn't matter-what matters is your quality of life.