Need advice on my body odor problem

This is my first time posting here hoping to get an advice from people that actually understand me. My b.o. issues started about a year ago after several cycles of antibiotics for different infections. People would start to make comments such as 'someone just shat themselves' 'ew smells like *ss' etc... Eventually I got depressed and my diet got worse than it already was. I kind of managed to get myself together and go out sometimes. I was away from the country where I had some friends that I'd hang out with. Im pretty sure they knew but never said anything even when i asked them. For a few months I felt as if i was unable to function properly. I did a little research online and discovered it could be because of toxins. I purchased cleanse and detox supplement. After I stopped taking it I felt much better and lighter. The body odor problems however continued and my diet still isnt good. I feel as if some days I smell and others I dont like I'd smell fine in the morning and by the end of the day people will smell it. The other day the guy by me remarked that it smelled nice there. Then couple days later someone saids it smells like shit. Im totally confused and not sure what the issue is. Right now my life is just terrible and school is just a nightmare. I dont even wanna go into friends&girlfriends...

I talked to my parents but they think im plain paranoid and wont take me to any doctor, I cant do it myself since im 17. After some more researching I think it might be candida. I purchased usana probiotic formula and started using it but i dont think thats enough and it also makes me constipated. I am aware that I need to change my diet but its really hard to eat healthy. Ive tried but occasionally I'd hear a comment about bad smell and just makes me feel like crap then my diet gets worse again... food seems like the only thing that makes me happy and unfortunately its soda and pizza... Im just really confused now and unaware of what to do next. Can someone give me an advice..