Why am I scared of love?

I’ve been talking to this girl for 4 months and we both really like each other. Then she tells me she loves me and it felt good so I told her I loved her. The next day I started freaking out about it, felt like I wanted to back away and I didnt understand why. I’ve never been in love before and I’ve never been hurt by someone. Anyways the next few days I kept it to myself and started feeling really down.. Then I talked to her about it and I think shes scared im gonna hurt her and that she knows I didnt really mean it when I said I love you. But shes accepted that, but knowing she loves me still scares me, like what if I hurt her? I really dont wanna do that. I dont know why I feel like this, why I wanna push her away abit.. But at the same time I dont. Everything was great and I really liked her sooo much til the ‘I love you’ thing came along. Anyone know why I feel like this? I just want it to go away and I want to really like her again, be like it was..