Love Failure and Mentally Upset, flower medicines

I am a male aged 30 and single.

once i was sitting near a girl in my office workplace. she use to talk sometimes. then her place changed.

now if someone comes and talks to her, i feel like i should also know what they talked.
if i was sitting near her then no issues, i will be happy that iam able to hear wat they speak.

but now iam always getting a feeling to ask her what they spoke and what their conversation was. (if they
spoke for 5 mins or so). I also feel like taking to her. but iam not a good speaker. i dont know
how to talk to a girl and what topics i should talk. but sill i used to talk to her sometimes.

sometimes if she sits near to someone and talks i feel jealous. i also told this to her,
after which she started to maintain more distance and will try not to talk to me.

Seems i like her, but she is married and also she is a nice person.

i know its problem related to mind. But I dont want to consult a psychiatrist.

Can you please tell me what medicines will help to clear these feeling out of my mind ?

Also there are few guyz who talk to girls. they go together for snacks and chat.
But i am not good at taking and iam a very shy person. Sometimes i talk nicely.
But sometimes i dont talk. Also i am bit elder than those guys. But i feel like i should
also join them and talk.

Please help me with some medicine so that these feeling are out of my mind,
and i dont disturb them. (they all know about my feeling. particulary the girl knows well.
but still she doesn't like me following her)

I have heard that flower medicines will help. any help ?

Thanks in advance
Kamal