Pain after sex.

Hi guys! Sorry if this is a bit long, I'm just really looking for some help. My boyfriend and I have been sexually active for about a year now. At first it was great! Everything went well and we both enjoyed ourselves (sorry if that's tmi). But about 4/5 months ago, it started becoming really painful to have sex. It would start of okay, but then in the middle of it I would start to have pain. It would almost fell like I wasn't wet enough. Then we'd have to stop and for about​ a week after I would have this burning sensation, and sometimes it will itch. Now my boyfriend and I use a generous amount of lube, so I didn't understand why this is a problem. If any one has gone through this and has some advice I would really appreciate it!