Validation
People who need attention or validation in order to feel secure must step back and learn to cope with that longing without acting on it. Otherwise they create a vicious cycle that will ultimately backfire. The more desperate and insecure you become, the less likely you are to be validated by others or to get the attention you crave.
Even if you do receive validation in this situation, it’s likely to be out of a sense of pity or guilt rather than freely given.
Thus, for your own well-being, you need to resist the urge to pursue validation from your girlfriend. Avoid the use of manipulation, guilt, pleading and covert reciprocal bargains, such as the unstated, “I’ll flatter you if you flatter me.”
Texting
People differ in how effusive they are in emails, texts, and on the phone. There is no correct way to be. Accept your girlfriend for who she is, and give her positive feedback when she is more affectionate or attentive in her texts to you.
When dealing with feelings of anxiety and desperation, remind yourself to resist acting on those feelings in order to avoid pushing her away.
Do something interesting
Instead of getting angry at her or sending a needy text, find other things to do during those moments of anxiety that will make you a more whole and interesting person. Once you focus on another engaging activity you will feel less anxiety. Moreover, you will become more interesting and desirable to her and others around you.
Decide what activities you will do when you feel lonely or insecure–read a book, learn a language, go for a run or a walk, play the guitar, write poetry, watch Ted Talks, or the like. Find a few interesting things to do and then develop the willpower and self-discipline to do them, instead of letting your anxiety and anger get the better of you.
It may be hard at first, and then it will become easier because you will enjoy doing your own thing. The result will be a more interesting, confident, and well-rounded person, who will be more desirable to be with. The bonus will be increased interest and attention from your girlfriend.