An explanation if you want one of why that happened:
Remember when you first started and had a good sized drop right at the beginning of eating low carb? That is because ketosis causes the body to store less water. It looks good on the scale and looks REALLY bad on the scale after you have been losing well. If you get out of ketosis you store water quickly again and it makes the scale go up and emotions get down. Although after being in ketosis for awhile like you have been you can occasionally get away with a day of a bit higher carbs, anything with a good bit of sugar or highly starchy will throw you out of ketosis, like the cake did, the cheesecake was just icing if you will that kept you from going right back in. If you get right back in ketosis you should have a good loss of all that weight again and hopefully some fat to boot. You should have a good weigh in next week or the next one, depending on how long it takes you to get into ketosis solidly. Some people do this intentionally to bust a plateau. The key is getting right back into ketosis. Keep it 20-25 for a bit and you will be fine. You've got this.