In need of some wise words!

Hey there, thanks for clicking!

I've been on a journey of self sabotage for a while now, I got over half way to my goal weight then gained it all back twice now. I'm really struggling to accept the scale and when I look at my body I still feel I look thinner even if the scale is the same. You should hear the excuses I have for filling my face it's unbelievable, exam stress, post exam celebrations, I burned load of calories today, I have to cook lots for my boyfriend anyway, people keep offering me huge portions, i'm depressed, i'm stressed, i'm bored, we have no healthy food, I have other things to worry about, food is just so damn tasty, yada yada. Excuses I use to make make myself hate my body more and ruin all my hard work! waa!

Moving on, I just joined a gym with my boyfriend- lost a pound in 4 days by making a huge deficit and gaining 2 back on the weekend. I hate myself! Been going 3 times a week, running around 2k (quite a feat for me!) rowing 2k and doing some strength exercises. It feels so pointless as nothing changes because I can't stop eating- is the gym futile without dieting? I just don't know!

I need a stern talking to! to tell me i'm being silly, to just keep enjoying exercise like I have been and stop making stupid decisions when it comes to food.

I'm curious, to lose say, 1lb a week with 3/4 gym sessions burning around 4/500 cal as well as 8 miles cycling 5 times a week to get to work and back, what would a non-computer suggest I eat per day?
I'm 5 6' and 140lbs aiming at 120ish. Eating 1200 in the past has made me lose really fast and I can't keep it up.

Also I'm aiming to hit 5k in one go with running, now upping and downing the speed on these treadmills is a mare, i'd rather just run y'know? can do 2k at 9kph, should I slow down and go longer or keep at my pace and gradually build the distance?

So many questions, so demoralised, but still going to the gym this afternoon!

Please help, gyms are a complete mystery to me and would like some advice as to what routines to do there also, but that's for another day when i'm a bit fitter hey.