Thank you for your question. I understand this must be a very stressful and distressing situation for you.
It is reassuring to me that you have a girlfriend and also many bisexual friends who can support you in your personal choices and other difficult life situations. Have you talked to them about this? How did they react?
I have some questions about your friend. How long have you known this person? Are his comments ill-intentioned, or was it just an inappropriate, though spontaneous outburst? Did he apologize? If your friend continues making hurtful comments like that to you, and if he does not seem to realize how important these comments can be, this would lead me to question your friendship. How important is this friendship to you? Does it tend to make you unhappy with yourself? These are the questions you should ask yourself before deciding to pursue a relationship with this person. If he is truly your friend, he should accept and respect your sexual orientation.
I also wonder what prompted you to disclose your sexual orientation to people in your gym class. You are saying that they now “hate you even more than before”. I assume from this that you did not have such a good relationship with them from the start, and they were not particularly intimate with you. What were you hoping for when you told them about your sexual orientation? Society in general is more tolerant nowadays, but there will always be individuals who have prejudice against gay/lesbian/bisexuals. It is prudent to choose who you want to disclose your sexual orientation to, and also to consider the consequences in special circumstances. On the other hand, if things have escalated in this manner, and you are now facing such a difficult situation, it could be worthwhile to change classes, if this is possible. To find out what exactly they dislike in you may also help…
Concerning your mother, although she seems opposed to you “deciding about your sexuality” now, it may be a relatively good sign that she does not depreciate bisexuals in general. Sometimes it takes time for parents to accept certain characteristics in their children that are different from theirs. This does not mean she will never accept you as a bisexual individual. Also, she can certainly help you with other interpersonal issues, such as those you seem to have with the people in your gym class, and which may have less to do with sexual orientation than with interpersonal differences.
On the other hand, it is true that sexual orientation and preferences are not fixed in time and space. You could also change your mind, and realize you are only attracted to girls, or to guys, or remain attracted to both. There is nothing wrong about being bisexual or lesbian: you should choose to be with people you like, and others should respect that choice.
Good luck, and contact us again if you have other questions,
Vi, for AlterHeros