Gym weight loss advice and cals HELP!

I basically need some advice here, I haven't exercised for a few years. Well the last few weeks I've been going to the gym.



I'm not a lover of anything other than cardio, it's not to say I will only do cardio! I'd just like to stick to just cardio for now.



However due to injury in the past in limited as to what I can do without ending up walking like a cowboy for weeks!



I currently do 40 minutes on a cross trainer burning 400 cals.



Followed by 30 minutes of constant breast stroke swimming (shamefully the only swim I'm capable off)



What I haven't mentioned is its all interval based, fast, slow, fast resistant hills. Slow, resistance and fast ... You get the picture.



This is at least 4 times a week!



I eat max 1900 cals a day!

I'm 26

6ft tall

Weigh 13 stone



Will I actually lose weight, or am I kidding myself here? Help is much needed. I do eat a balanced diet as well now, no junk or stupidly fatty foods on regular basis.



Thanks for reading!