So there was an imbalance in your relationship with your gf. She's your everything! But it sounds like she felt smothered by your needs. So you thought. OK, I am too reliant on her, I will get other gfs and friends to support me. But when you got other sex partners, your gf got jealous? She doesn't want to feel pressured to be your everything, but when you got others, she then felt jealous?
Yes, becoming a bit more self loving and self reliant is a good idea. We all need a foundation of self caring.
As RuPaul says, "If you don't love yourself, how in the hell you gonna love anybody else?" Your love for her might feel, to her, like a drowning man clinging to her as a life raft.
Of course, this kind of desperate, one and only, you're my everything forever and ever "love" is totally supported in our culture, in our media, in our dreams of fairy tale weddings and happily ever afters. But, this dream is a lie. Especially if you are really wired for polyamory (as many of us here are). I'd say it's too soon to tell with you if you're wired for "one and only" love, or for multiple loves. You need to work on yourself, your self love.
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
Mags (poly, F, 60) loving miss pixi (poly, F, 38) since January 2009, living together since 2013
also loving Punk (monogamish, 42, M) since Oct 2015
"Master," (mono, 34), miss pixi's Dom for 2 years