Because Stress keeps coming back.
Your mind does not like being stressed, and will do what it has to, to calm down. Junk food is high salt/sugar, which numbs things down a bit, to make it easier to deal with.
Since we cannot numb the situation, we numb ourselves.
Check it out sometime, see ...
If you feel you are 'bothering' people, you may just be wrong.
Lean on your support network when you need it; that is what they are here/there for. Do not abuse it, but, let them know they are appreciated when you do call on them.
If you feel pressured by others to drop weight. Relax, this is your life, and your choice. If they mean well because you asked for support, but, are now smothering you. Let them know you love them, but, you need some space. Be nice and they'll be nice back.