I took two pills intead of one this morning - Divisions by zero

I’m on Elvanse (lisdexanfetamin) 30mg I just took two pills instead of one by mistake. I’m quite sure I wasn’t noticing anything with 30mg but now I fear an overdose or some shit. Tho here if 30mg is not enough they jump you to 50mg which is not far from 60mg… The thing is that I’m scared and don’t know what I should do.