Help with stress and subsequent eating

Hi

I'll try to keep this short as I can but I'm looking for some general advice on the above. Back in July I was super fit and a strong runner and ran a 10k road race. I pushed myself a bit too much and ended up very tired for days on end. This coincided with an exam and my own birthday and ended up taking 3 weeks off training, losing a lot of fitness and gained a stone due to poor eating habits.

I then tried to pick things up from where I left off but the loss of fitness affected me plus work got mega busy (I work in software support and there is strict targets around call handling time) and very stressful. This I didn't handle very well and This then led to the taking the rest of the year off and again my eating habits were poor and I gained a further 4 stone.

I've started 2015 pretty well with 4 weeks training and clean diet, lost a stone and a half but now work has got even busier and the stress has crept back in. I've been that stressed out these last two days that all I've wanted to do is go home and chill but I've ate poor as a result.

Can anyone share any tips on on how to not let the stress get to me or at the very least if I've had a stressful day share any tips on how to motivate myself to exercise that day. I know they say that exercise helps with stress but I feel it's easier said than done at the time.

Two ideas I've got myself is have a pre-workout drink before I leave work which would get me 'buzzing' for the gym (don't really want to rely on this though) and instead of going straight for the bus instead go for a short walk to relax the mind.

Any responses will be much appreciated.