i'm not an expert but it sounds like you have a good exercise plan forming.
i call my treadmill the "dreadmill". i have mobility issues and can manage 8 min's/day at a slow pace. but, it's what my body allows so that's what i do.

i think it's important to find something doable. then make a plan and follow thru. i put stickers up on my wall calendar each day i walk as a little reward, and as a reminder that i need to walk that day.

i believe it's recommended that one do 30 min's of a cardio (where you raise your heart rate) 3-4x's/wk. HOWEVER, you must listen to your body. know your limits. find something that's doable. that way you'll be successful.

as to the eating i would suggest you start to read labels. watch the sodium (salt), carbs and sugars. fresh veggies and fruits are good choices.

when i first started i saw a RD; registered dietician. she helped me come up with a reasonable but healthy plan. her advice was invaluable. well worth the $$$.

i understand your struggle. i lost 40lbs over a yr and put 20 back on. now i'm fighting again.

you CAN do this. i commend you for starting. that's often the hardest part.