Should I stop breastfeeding?

My son is 18 months old. We’ve gone through a trialing period since he’s been born, but he’s always been EBF

he does really well with BF and now that he’s 18 months old he truly loves it, it’s fun for him, it makes him happy he comes running for it if I call him

Now here’s my dilemma, I want to go back on vyvanse. Prior to pregnancy I was diagnosed with ADHD and binge eating disorder, vyvanse helped A LOT.

Since having my son I’ve gained 80lbs, all due to binge eating and external stressors (I’m a single mom, divorced when my son was 2mo).

On one end I’m dying to go back on vyvanse and get my own life back on track, on the other hand I’m facing guilt of taking him off BF.

My mom is also against me stopping BF (she lacks education about mental health, so she doesn’t know I want to go on vyvanse), she believes I should BF until my son is at least 2

What should I do? I’m really struggling to decide