Healthy Natural Weight Loss ASAP?

I am a 21 yr old female @ 167lbs. This is the heaviest I have been in years and I need help to get the weight off. Usually I am 150-155 and I still wasn't happy because I know it's not the healthiest I should be at. I have no physical limitations-- but I did learned I am borderline hypothyroid which finally made me understand why even maintaining my weight has been such a struggle. I would prefer to not take any prescriptions or dangerous diet drugs-but OTC supplements with multiple benefits are encouraged. Right now I take a GNC multi-vitamin and 2tbsp of ground flaxseed in whole milk every morning .I have been exercising close to never( which is half the problem and I know that) because I just don't know where to start. My Goal is 116-133lbs. If I was around 124-125 mark to give myself some leeway that'd be ideal.I would like to be toned & lose inches/m.The weight on the scale is important but I want to be physically smaller and healthier. I would like to do the things that will have the greatest impact as possible. What can I do on my own- in my home or outside, and not in a gym? Any tips/advice regarding specific exercises ,diet&nutrition?