Why is it so hard to be bi ?

I came out to four people . I am a 14 year old girl btw . The first one called me a dyke . The second one is still my friend but she treats me weird and makes fun of me for who I like . The third is totally chill about it . The fourth was my best friend and now she is the love of my life . I told her and now she only talks to me if I talk to her . How do I get over her ? And will people always be this not understanding about me being bi? I mean is it really that bad ?