walaikum assalam rahmatullahi barakatuh
No it's not haram to tell people what you asked in your dua but if it's something that you'd rather keep private than that's upto you
There's no need for 'signs' that dua is accepted as every dua indeed is accepted, but Allah knows best what to grant in this world and what to in hereafter so the ones you don't get in this world, you'll be rewarded for it in hereafter
