Hit a wall - Why has progress stopped

Your calories are too low. 1000 does not provide you with adequate nutrition.
Please raise them back up to losing 1 lbs a week.
With such a low calorie goal you will become lethargic and your normal activity level will drop. This will in turn mean you will need less calories than one needs for a sedentary activity level. You could also develop health problems.

As to why you aren't losing. Without much information, the most obvious thing for you to look at is your logging. Make sure you are using a digital scale to weigh all solids. Liquids can be measured with cups and spoons.

If you put it in your mouth; put it on the scale first.

Double check that you are using accurate entries also.

If you haven't been for a check up since you started losing weight make an appointment for one. There are a number of problems (thyroid, hormone imbalances, etc) that, if left untreated, can affect your weight loss.

If you post your stats, goals, and make sure your diary is open you will get more specific help.

Cheers, h.

IMHO @middlehaitch 's post nails the key questions.

I note that for 26 YO woman of 5'5" (I just picked an average height) that the difference between BMI of 30.2 and BMI 29.9 is 1lb, so there is no reason to panic - You could (not suggesting that this is the best or your only option) drop that by eating low carb for a couple or three days before your weigh in.

When is your weigh-in appointment?

I think that there are two things being discussed here.

Whooshes are a frequently seen phenomenon as part of normal weight loss. This is where a dieter will see their weight drop in "chunks" rather than a more linear (a little bit each few days) pattern.

The thing that I mentioned is more of a trick to show a lower scale weight for a specific weigh-in. It's something that sportsmen and women sometimes to to make a weight classification for their sport (like in boxing where the competitor must not be over a specified weight). In this instance, the "dieter" is manipulating their glycogen stores and therefore retained water to reduce weight - the weight reduction is not fat loss.

So, this second method is a bit of a cheat really, but it a tool that you may want to fall back on if you can't make the weight by fat loss.

So, moving on...

I still agree with everything that @middlehaitch says.. I think you need to be eating more and suspect that lower calories plus the stress of the IVF deadline are contributing to your lack of loss recently (Cortisol increase = fat retention). So, keep calm and carry on with a moderate deficit. Don't do anything stupid or be looking for any quick fixes (until few days before where you may want to look at low carb for the glycogen/water losses as mentioned above)

Water retention due to hormones. Guaranteed. Guessing your period is due soon (or ending)?

I only ever lost the week after my period (sometimes 6 pounds at a time too), then nothing until the next one.

Do you use a food scale?