How to read old text messages?

I have an IPhone 4S with IOS7 with Verizon. I want to read an old conversation between me and my boyfriend from like 4 1/2 months ago. I've tried going to the top and clicking see older messages but that takes forever and my phone starts to freeze. I never deleted the conversation or anything. Is there any way I can go right to the conversation? I know the day and time it happened.