Hai! I think this is perhaps a common problem in cheese homemade production.
This is normally caused by two things: Either the cheese was not drained enough, or the cheese was not salted enough. Add a little extra salt, stir, and try to get some more whey out. If you happen to have a cheese press, give it a shot here. Wrap your cheese (even if it's soft) in a cheesecloth and press at 10 pounds of pressure for 15 minutes. Then taste again.
Cheese can also become too bitter with age. If you made ricotta three weeks ago and it tastes bitter, it's probably better just to discard it.
From the article: Troubleshooting Homemade Cheese - Cultures for Health
I hope it helps.
Selamat belajar! :)