Yet another Net Calories question...

I am not an expert but my thoughts on this are:

Your net calories should be at a minimum 1200 calories. When you have more weight to lose you can get away with not eating so much and still lose weight. When you only have 20lbs or less to lose it is more important to make sure you are eating the calories or you won't lose weight. I don't know why or what the logic is but this is what I've read in a couple of places. I would still recommend that you try and eat more though.

I understand that to many the concept of eating your exercise calories and "Starvation Mode" can seem counter-intuitive or mythical, but I would urge you to take some time, go "back in time" and start reading threads where people have been hitting a plateau.

These people are always close to their goal weight. They always work out an insane amount, usually large amounts of cardio. They NEVER go over their calorie goal and are usually under it. They rarely eat back their calories. They eat a really balanced diet and rarely break from their diet. They lost a lot of weight right off the bat, but now they just DON'T understand why they haven't lost any weight for a month.

Most of the time, these are people who have set their goals to lose 2 pounds per week at 180 pounds or have 800+ calorie deficeits on average. If you don't believe me -- go look. Not everybody accepts that the root of their problem is undereating, but there is definitely a pattern that develops.

Here are some helpful links from experts or testimonials from MFP users that agree:
http://www.myfitnesspal.com/topics/show/113609-relatively-light-people-trying-to-get-leaner
http://www.myfitnesspal.com/topics/show/175241-a-personal-view-on-exercise-cals-and-underfeeding
http://www.myfitnesspal.com/topics/show/10589-for-those-confused-or-questioning-eating-your-exercise-calo
http://www.myfitnesspal.com/topics/show/61706-guide-to-calorie-deficits
http://www.myfitnesspal.com/topics/show/174065-starvation-mode-is-real-and-ugly
http://www.myfitnesspal.com/topics/show/6556-the-answers-to-the-questions

Here are some examples of links that demonstrate exactly what I'm talking about:
http://www.myfitnesspal.com/topics/show/3047-700-calories-a-day-and-not-losing
http://www.myfitnesspal.com/topics/show/8199-off-to-a-slow-start-actually-still-at-starting-gate
http://www.myfitnesspal.com/topics/show/193743-weight-not-changing
http://www.myfitnesspal.com/topics/show/193705-trainning-and-going-nowhere
http://www.myfitnesspal.com/topics/show/193600-how-to-i-drop-the-last-7-pounds
http://www.myfitnesspal.com/topics/show/193589-major-plateau
http://www.myfitnesspal.com/topics/show/193461-hit-a-plateau
http://www.myfitnesspal.com/topics/show/192990-tips-on-breaking-a-multi-month-plateau
http://www.myfitnesspal.com/topics/show/192909-hit-a-plateau-any-advice
http://www.myfitnesspal.com/topics/show/190450-i-know-i-know-but-help
http://www.myfitnesspal.com/topics/show/185964-plateau-d-advice-needed

Cited Studies:

http://caloriecount.about.com/truth-starvation-mode-ft28742
http://unu.edu/unupress/food2/UID07E/UID07E11.HTM
http://www.ajcn.org/content/68/3/599.full.pdf+html?sid=e89fb416-23c9-4726-9f6b-2755536995a5
http://www.ajcn.org/content/60/1/29.full.pdf+html?sid=5deb5c19-82fc-46dc-bf19-5dc7842a779a
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=8777329&dopt=AbstractPlus
http://www.ajcn.org/content/47/6/981.full.pdf+html
http://www.ajcn.org/content/56/1/230S.full.pdf+html
http://www.ajcn.org/content/39/5/695.full.pdf
http://www.springerlink.com/content/vl488623pn1q0219/
http://www.annals.org/content/130/6/471.full
http://www.nature.com/ijo/journal/v22/n6/pdf/0800634a.pdf
http://www.ncbi.nlm.nih.gov/pubmed/8696424?dopt=Citation
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=7489033&dopt=Citation
http://www.springerlink.com/content/t462u540t7151722/
http://findarticles.com/p/articles/mi_m0689/is_n3_v41/ai_17516395/
http://www.jacn.org/cgi/content/full/18/6/620?ck=nck
http://www.ajcn.org/content/53/4/826.full.pdf+html
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=2341229&dopt=Citation
http://www.ncbi.nlm.nih.gov/pubmed/2613433?dopt=Abstract
http://www.ajcn.org/content/49/1/93.full.pdf+html
http://www.ajcn.org/content/45/2/391.full.pdf+html
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=6694559&dopt=AbstractPlus
http://www.ajcn.org/content/57/2/127.full.pdf
http://www.ajcn.org/content/51/2/167.abstract?ck=nck
http://www.nature.com/ijo/journal/v32/n3/abs/0803720a.html
http://win.niddk.nih.gov/publications/low_calorie.htm

I am exactly the same as you. I have lost the weight I wanted too and am now trying to get fitter and be healthy (hence why I like to record what I eat)
However I usually eat around 800 calories and am so full at the end of the day, but everyone on here keeps on telling me I am eating way too little and need to eat 1200 minimum. Yet if I do eat that much I am so full I have to force myself to eat it.

I have no idea what to do :S

You're probably fine right now, but losing weight will probably get tougher the closer you get to your goal weight. What you're doing will tax on your metabolism over time (weeks and possibly months). Good luck with your weight loss and if you run into a plateau, you know the answers for how to get back on track.