Will these feelings last forever?

No feelings last forever, whether we are
talking about negative or positive "feelings". These "feelings" can and will change and that is okay and normal. This is true from feelings of sadness and even love. In the case of love as an example, we must choose to accept someone and love them regardless of flaws, the "feelings" of in love might come and go,
but when you choose to love someone, as
long as you are not in an unhealthy scenario of course that might be a close a definition of "true love" as we can muster without incorporating peoples perceptions. If you are feeling something else, perhaps something we assign a negative connotation to take heart that the feeling is not a permanent one, if just that little bit helps than than you are doing great.

Also, the feelings will remain, you will just become adaptable as time passes. It might be possible that they won't last long. The thing is you will be over them, just give them some time.

Everybody is different in the ways they think and feel or can handle a thought or a situation. Finding the "Right" type of help is a good route to take whether it be in the form of therapy, counseling, coping mechanisms, medications or the combination of all.

Feelings come and go, but all feelings are
worth it, whether they are good or bad. Just focus on being in the now and focus on how you feel and staying content with how you feel also.

Sometimes we just need sometime to heal, other times we need to talk to
someone and express our thoughts, and other times we may need to seek professional help.

Things can always get better. Don't lose your hope.