Your saying you miss her and want to see her more sounds needy. It's probably true that you do miss her and want to see her more but you need to get out of that mindset or you'll never keep a girl around. Women want a guy who wants them a little less than the woman wants the guy. If you are missing her and pushing to see her more frequently, then this sends her the message you are into her more than she is into you. Women HATE that. They want a guy who is busy, happy, has a good social life, and is happy with or without her. He enjoys her company when he's with her but when he's not, he's busy and happy doing his own thing and if she were to disappear, it wouldn't really matter to him. I know it sounds messed up but it's the reality of the situation and the sooner you get that, the sooner things will really start changing for you in a positive way.
The BEST solution is to get to where you are more successful with women, are seeing several at a time, and are just generally busy with your work and social life (friends, other women, etc). You are depending too much on this one woman for your happiness and it's needy and women instantly recognize this and it's a major turn-off. Instead of dwelling on her, start casually dating other women until women are abundant in your life and you aren't attached to just one (unless you truly want to be and she is more attached to you).
While you are working toward that, there are tactics you can use to help at least appear like you've already accomplished the above
- When she gets distant (in communication and availability), you respond by getting even more distant.
- If she's a little distant or pushing for space (like it sounds like she is now), only initiate contact with her ONCE per week, and do it to set a date on a specific date/time/location. If she doesn't agree to it or suggest an alternate date, walk away and never look back. Do NOT initiate contact with her again for any reason.
- If she initiates contact, assume it's because she wants to see you. Exchange just a few messages but then invite her to a date on a specific date/time/location and follow the same rules as the previous bullet point
- Avoid texting back and forth except to set dates. You are "busy" and don't have time for that. Attraction is built in-person, and during time apart when you give her the space to miss you (which means you aren't talking to her over text or phone)
- Don't say things like, "I'm staying home alone, by myself, instead of seeing you." Say you "already have plans." Let her wonder what you are out doing and with whom. Have some mystery.
Also remember that if you start getting more distant as I suggest above, and you become worried that doing this will result in her leaving, know that this is what was going to happen anyway. There is nothing you can do to convince a woman to stick around who doesn't like you. Usually what happens is women decide they aren't into you anymore, but are willing to be wined and dined and doted on and validated by you with zero investment on their part for another few weeks or months while you chase them. Then they dump you. The ONLY fix is to respond to distance with more distance and know that if she actually likes you, she'll reach out to you.