Not sure what to title this

It's has been years since I dated and liked someone, but recently I'm developing feelings towards a friend. Since I was away from relationships for so long; I no longer know how to approach the situation because of that I'm being conscious of my actions, so I don't look desperate; however, it's hard when I feel really strongly towards them. I fear that these feelings will eat at my mental health because I tend to overthink a lot and dwell on the past.

Any advice or words of encouragement would be helpful, please and thank you!