Liver is probably best....I'd want your RDA of iron or above each day.
Chicken liver can have some yucks if it is grain fed; I think arsenic. Just to let you know.
If you want a supplement to make up some difference in your needs vs. intake ferrochel ferrous bis-glycinate form of iron taken with vitamin C at very low levels (RDA or slightly above) will get iron back to normal very quickly. http://www.indianpediatrics.net/aug2004/table1.htm
But I'd take it away from the liver source. In general, whether with meat (heme) source or non-heme source of iron, you can't absorb really large amounts at the same time. Because you are so deficient you will probably absorb better at least initially. But if you can space out doses that will help. http://jn.nutrition.org/cgi/content/full/133/7/2214#T1
I would do vitamin C (sodium ascorbate or food source) with every meal or snack for the time being. That will help you maximize iron in grains and other non-heme sources.
You need to avoid iron inhibiting foods with your iron. Those include eggs (yolk and white), red grapes and raisins (most dark fruits are going to contain inhibitors), nuts and seeds and legumes (including soy), calcium containing foods or supplements including dairy, spinach and some other greens (not all--those containing oxalic acid). A few of those foods are so bad that in enough quantity they can block iron all day so I would avoid them completely--especially egg. Dairy just keep away from the iron. Use vitamin c to take care of other inhibiting factors. I can't find my really good link showing that egg will block the entire iron in the diet (if you eat enough) but this link shows it does block iron--even more than dairy or soy which are known inhibitors. http://www.ncbi.nlm.nih.gov/pubmed/17995699
B12 shots are the way to go for that deficiency.
I bet with those numbers you do feel awful. I hope it all improves soon.