<human>: Could you distill the essence of the text into 1-3 sentences?

Hi all, 

As titled, been working here for just a few months. It's recently come to my realisation that I have been harbouring feelings for a colleague. The usual stuff which comes with the territory - butterflies when she's around, I smile and am in general happier when she's around, mildly jealous when she flirts with other guys and just wishing that I could be spending more time with her. As of now, we smile and greet each other when we bump into each other, and have been on a few lunches as a group with other colleagues. 

Just to get this out of the way, my company does not have a don't date your coworkers policy, and we aren't in the same team and are peers in terms of seniority. 

I've never really been successful with relationships. Only dated one other person which ended last year after 3 years together. So I generally have self-esteem issues when it comes to women and have a compulsive irrational, tendency of assuming the worst case scenario out of any perceived sign of disinterest and getting discouraged. These are issues I've acknowledged and am in the midst of seeing a therapist to work on, but if anyone has any tips to curb such tendencies I'm all ears. 

Today was a pretty emotional day for me. She's going away on an assignment until November, which sucks. I'm hoping that when she gets back, we'd be able to get closer as friends and who knows what next. Being the new guy, it's harder for me to break into circles of friends which are already established, altho I am making an effort to blend in with everyone (trying as best as I can to not show any bias). It's been tough acting like nothing's up, and I'm worried that I'll do something cringey along the way.

Anyone with similar experience mind sharing how they coped? Apologies for the rambling format.
<bot>: New Workplace. Want to break into a new circle of people, get closer with a colleague and not drive myself insane in the process.