Below is one of my replies to a very similar topic, as you mention being screwed over constantly by being a "nice guy", I think you may find some of it beneficial
source:
Friendzoned
"As someone who got crushed with the friendzone as a nice guy for many years I have a few things to let you think about.
1) If you're speaking to a girl you like who has recently broken out of a relationship, don't be the guy to offer emotional support. Girls love drama and gossip. She will list all the things her ex has done to piss her off. You may see this as an advantage but it's really not. Chances are she will see you as a friend who can give her support and attention 24/7 (just like some of her female friends). She will friendzone you before you even know it, and you'll misread all of her signs as false attraction. Then you will be hurt.
2) Being the nice guy can actually you not being honest to yourself that you're being manipulative. You're going out of your way to give a 10/10 impression, which you wouldn't do with your male friends or any female friends you're not attracted to. This will always result in failure as she has your attention too easily.
3) Don't try girls who have ex's or current boyfriends/flings close by as it's 9/10 times a waste of time as their main focus is on that other guy. If these guys in question are 'getting in the way' they've read you from a mile off and are protecting 'their girl' from you.
4) Keep busy and put your activities and/or studies/career before replying to a girl (if text/online interaction etc). Replying instantly has no game and girls lose interest quickly as they no longer find you mysterious and may even see you as emotionally immature.
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It is hard to fully understand your situation as there are so many possibilities and there is no magic formula to seduce women. It either happens or it doesn't. Trying to find a magical solution is being the manipulative nice guy who doesn't realise he's being selfish.
I've been there believe me. I've had points in my life where i was acting all fairytale and thought 'she' was the only one. Other times I've been the 'insecure player' who thinks because he's speaking to lots of girls then one will magically jump into bed with him.
Just keep focusing on improving yourself, and not trying to be someone you're not. Develop different areas of your life and you will become a person with diverse interests and fun to be around. Keep trying with girls and accept rejection although it can really hurt sometimes. Trust me, a few months down the line you may even silly for liking a girl so much.
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I hope that somewhat makes sense. I could go on forever about my past experiences but to be honest what my conclusions are of my past are just the conclusions i've come to and may be different from you or anyone else.
If you feel a bit lost and unsure where to begin. Do by all means do some online research.But don't sign up to any bullshit courses or communities which claim they have secrets to seducing women. There is none. End of story.
The closest you can get is understand social cues, and actually trying over and over again.
As the cliche goes, practice makes perfect."