1)the consistency and color of your wetness/discharge can change over time, so i wouldn't worry too much about it. 2) could be a-lot of things, what's different? is there adequate foreplay, are you giving/getting head? are you switching it up in the bedroom, trying different things, or is it missionary city? For now i would say try to use lube to at least make sure you don't get a yeast infection from dry sex.
Maybe you're not as excited about the guy.