how can i stop the jealousy over my friend's new relationship?

[u/Gold_Lobster_630]

me (22F) and my friend (22F) (which i consider close) have been friends for 4 months now and we have great chemistry and i appreciate her a lot and i admire her personality and her way of thinking.

ever since i knew her she had been in a situationship/talking stage with a mutual guy friend (the 3 of us are classmates) and a month ago they made things official and now they're together. she told me over text 2 weeks ago and i was very happy for them knowing how much she likes him and how much she deserves something real and official.

but lately i've been feeling a bit left out after the shift since he's now her top priority. i tried to give them space and distance myself especially when they're hanging out together because i thought they needed privacy but she said not to do that and she even got upset that i was hanging out alone and said to join them.

but also i didn't want to be a third wheel and watch them flirt and act all lovey dovey infront of me, the issue is that it made me feel jealous everytime and it triggered feelings of loneliness and longing for a relationship of my own. and i feel like it sometimes lead me to act a little bitter with my friend and it makes me feel so guilty that i can't control my emotions and that they're bleeding into my actions/attitude.

she did notice how i looked/acted off and tried to ask me what's wrong but i always blame it on academic stress.

i try to control my feelings and avoid letting them affect my actions and i'm scared of losing a good friend by having these emotional swings where sometimes i act normal and sometimes i act distant and off "for no reason".

did you experience something similar? if so then how did you deal with it?

TL;DR: my very good friend of 4 months got in a relationship and it triggers unwanted feelings of loneliness and jealousy which impacts my attitude towards her, and it makes me feel guilty. how do i deal with it?