Well allow me to begin by giving you full props on your willingness to share with us all your progress... as this i'm sure proves to be helpful when the inner lazy man tells you that skipping your morning walk won't be that bad.... fact is that it begins a domino effect which allows you to skip more and more.
I too have struggled with the issues of weight..... I am 5'10" and at my worst weighed in at 240, you may be saying "thats not so bad" well thing is I gained that weight in just under two months going up from 185... so guess what I got stretch marks and everything around my stomach as if I were pregnant....since I am a man that would be impossible... or at least improbable( I've seen the news about that trans gender guy-gal)
fact is I began work driving trucks, and learned to love all the greasy disgusting growl you can pick up at most any fast food restaraunt or truck stop.... Hence began my trek into the world of health and fitness, which I have studied with great interest, and learned so very much....
first off let me say mlambert knows what she is talking about, you can take her advice as it seems to be well versed and known with depth.... throw away that stupid scale as it will only mislead you....let the tape measure become your new friend...as it's readings are true and exact..... start your day with 1 litre 32ounces of water, then have breakfast as soon as you return from your walk(or shortly thereafter) incorporate whole grains and lose the white bread...eat lean proteins and lots of veggies,they will keep you feeling at your best...and when sluggish, coffee or green tea will not only provide you with antioxidents but the caffiene will perk you up and curb your appetite...
as mlambert already said eat small but eat frequently... I do 200-300 calories every 2 1/2 to 3 hours...and nothing within 3 hours of bedtime.... to lose weight I recommend along with your cardio, incorporating free weights, in fact I love them, they help build bone density and grow muscle as well.... keep the lbs. to something at the 10 to 12 rep range for 5 sets per body part...with rests lasting no more than 35-40 seconds between sets and 1 minute between excercises or bodyparts....start at your core and work your way out exhausting prime movers only after they're no longer needed as secondary movers... for instance, when doing bench press your prime movers are pecs, with your bis and tris as secondary muscles, so do chest, then bisceps, then triceps...always biceps before triceps otherwise you'll hurt your elbows... then on a different day do your back and then shoulders, and another day for legs... remember core out...
As for the multivitamins, I can't comment as I have devised my own regiman, primarily focused on supplementing with vit c, vit e, and b complex... i try and get most everthing else from eating natural fruits and veggies, again this is my way and can't recommend it for everyone...it's just I've found the multis don't give me enough c and e...
Well I've probably bored everyone to death so I will end for now, if anyone has any questions, just pm me, as health and nutrition have been my hobby for about 15 years....
Good luck with your endevours....and by the way, one last thing, Matt Furey has put out a program called combat conditioning which uses various bodyweight excercises... such as back bridge, hindu push up, handstand push up hindu squats(no weight- high reps) I highly recommend this program... great addition to your cardio and free weight regiman.