You're probably in the dreaded Friend Zone by now.
When you spend a lot of time with a girl and never do anything more than act friendly you're basically condemning yourself to be seen by her as just that, a friend. Women tend to live through their emotions a lot more than men, and if you're not creating any kind of attraction or arousal in them then you're going to be looked at in a completely platonic way. There is simply no way you can logically convince a girl to be feel attraction for you, regardless of how you feel. Risking chasing her away by telling her is infinitely preferable than doing nothing and beating yourself up about it, and it's not fair on her if she just sees you as a mate and you harbour feelings that will probably bubble up in some sort of embarrassing outburst down the line. If she doesn't see you that way then what are you ruining by telling her? Your fairytale future together? That kind of speculation and expectation isn't conductive to happiness.
It's allllways better to communicate your interest early on so you're not wasting each others time and she knows you find her attractive and you avoid the classic 'friend who wants more' scenario, which is depressingly common. The window of opportunity exists, and it's never open for long.
Anyway, rather than delivering some sort of 'I really like you!' speech, take her out again, be flirty, initiate light physical contact, see how she reacts, and if it's going well tell her you want to play Dr. and Patient, it's time for her medicine so she should close her eyes, then kiss her.
Also never utter the 'deserves better' thing, self-belief goes a LONG way.