Please tell me what to do

Hi! So i don't know anyone else who i could ask so please help me
I have never talked to a boy before although im already 20 because i went to all girl's school plus I'm an introvert and super shy
But there was that boy i liked and i tried talking to him and it was awkward i just greeted him and asked him how he was doing that's it and we never talked again...
Now there is a boy at college who tried to approach me months ago but i wasn't like doing good mentally and physically so i kinda turned him down but at the same time i like him I don't know why but i do and he told me last time we spoke that I'm free to talk to him whenever i want...
I want to message him now but my sister and my bff keep telling me no and i shouldn't do that and what if he already lost interest i would feel like shit
So what should i do should i text him or not?
Sorry if there are any mistakes my English isn't that good ╮(￣▽￣)╭