Note: Allah Never Leaves. Let People Come And Go.

💐 In The Name Of Allah The Most Gracious The Most Merciful
💌 When some users unfriend you, block you, un-follow your posts, reject your friend requests, or leave the group chat you added them in, do not start questioning if there is something wrong with you. Some people weren't destined by Allah the Most Wise to enter our circle as friends, but random strangers briefly passing by. 
Think of that time when you declined a friend request from a user whom you aren't familiar with, that instance when you left a Facebook group because its theme had nothing significant to do with your interests and goals, and that moment when you unfriended a user because they posted a controversial status update which triggered negative emotions. Your rejection of a user's friend request, disappearance from an online community or decision to no longer associate with certain individuals do not decrease their value as human beings with rights, beliefs and responsibilities of their own. It just means that your mission in life and priorities are too different. Exposing yourself to matters which you disagree with or can't support only bring about disharmony, guilt and emotional discomfort. Hence it is your right to carefully select the type of content to consume, information to absorb and like-minded souls to surround, ones which positively motivate you to become a better version of yourself rather than the other way around.
When some people exit from your life and treat you as one of their past memories or a forgotten stranger:
1] Be gratefully contented Alhamdulillah that while they walked away, Allah Subhaanahu wa Ta'aala never left, and Allah won't abandon you so long as you strive to be among Allah's faithful servants.
2] Did those ex-friends give birth to you, dutifully pay your bills or keep supporting you financially without expecting anything in return? No? Then you're not required to get emotionally attached to them. Detach from them especially because peace of mind cannot be achieved by attaching yourself to what is fragile, imperfect and temporary.
3] Your duty as a Muslim is to serve Allah Subhaanahu wa Taa'ala only, striving to be the best Muslim servant whom Allah wants you to be, not to force Allah's creation to agree with your beliefs and resemble you exactly.
Accept that all humans don't have the exact same role, tastes, temperament, experiences, and understanding. A subject you're so enthusiastic about may be viewed as uninteresting to another, just as you may find someone else's focus and hobbies not that interesting. So whenever somebody leaves us, instead of feeling deficient or incompetent, be contented knowing that we still have Allah Subhaanahu wa Ta'aala, the One Who'll judge everyone with mercy, wisdom and justice on the Day of Judgment.
📖 Abu Huraira RadhiAllahu 'anhu narrated: Allah's noble Messenger Muhammad SallAllahu 'alaihi wa sallam said, "The strong believer is more beloved to Allah than the weak believer, but there is goodness in both of them. Be eager for what benefits you, seek help from Allah, and do not be frustrated. If something befalls you, then do not say: 'If only I had done something else.' Rather say: 'Allah has decreed what He wills.' Verily, the  phrase ‘if only’ opens the way for the work of shaytan."
Source: Sahih Muslim 2664
Grade: Sahih (Authentic) according to Muslim