If you only have this one friend, you do need to get other friends so the one friend does not feel you are trying to interrupt her life instead of having your own. If you need someone to listen and help you with your problems; a professional might be more useful in the long term than using a friend that you are not with in person daily, who does not see you and interact with you daily in-person.

If you worked with or went to school with or commuted with this friend, there would be time in each of you all's day if you wanted to talk and catch up; the internet is not the place for "listening" though, unless it is in a forum like this one where we all deliberately come here for this purpose.

Friendships have to be spontaneous and natural or they can become one-sided and a chore for one or the other person. That you believe you are there for your friend all the time but they are not there for you, is your perception; what your friend wants and needs only she can know, we who are there for friends cannot know their wants and needs, unless they tell us and sitting around waiting to fulfill other's needs as we see them can skew our own lives. We are in charge of taking care of us, not anyone else.

Relationships are not about keeping score at all, or even "give and take" but about relating and relating is always two-way at the same time, not like walkie-talkie/radio where only one person can talk and one listen at any time and if you "interrupt" you cannot hear them or they, you. Relationships take a lot of practice and meeting and getting that practice with a lot of different sorts of people.

I would join a club or group around a current interest you have and make new, in-person friends so you have access to more in-person help and can keep your mostly phone/texting/Internet friends too but have fewer problems with wanting someone but not having someone close enough to be able to help in a more realistic "life" fashion.