Where am I going wrong?

im not the skinniest of people(ok im fat!)due to take aways,working long hours, not eating at regular times, nightshifts etc. i did no exercise other than being on my feet 13&a half hrs a day(im a nurse) so i decided to kickstart myself into losing some weight in a healthy way. started to eat a bit healthier, not eating after a certain time, 3 healthy meals a day(a typical meal day is bran flakes with semi skimmed milk for breakfast, lunch is a small bun with ham and salad in it and fruit and plenty of water, tea is a piece of salmon with pasta on an average day). I've even started riding my bike to and from work which kills me because I'm so tired but its the only kind of exercise I can fit in etc! Ive been doing this for 2wks and this wk alone I've gained 4lbs!!!! I don't look any slimmer, my legs,thighs,ocks etc feel firmer but I don't look like I've lost weight AT ALL!! my clothes don't feel like they are getting loose! my colleagues are saying muscle weighs heavier than fat but I'm not impressed with the fact that the scales are going UP not DOWN! they say I don't look like I've lost any weight either wen I ask them if I look like I've lost weight etc. so can someone please advise me where I'm going wrong&any advice please? any advice is appreciated! I work full time as a nurse and do shifts etc which can be all over the place like nightshifts etc. I really don't have timeto go to a gym as I'm also a full time carer for my father so I don't really have the time to go to a gym etc. no nasty comments please!