Plantar Fascia problems need to be attacked from 2 angles.
The first is to attack what is causing the PF in the first place. It is usually caused by poor biomechanics, most likely (as Slogger has already said) pronation (rotation of the foot inwards, like Elvis' wobbly leg dancing) or, more unusually, supination (rotation of the foot outwards). Quite often people also develop Achilles Tendon problems, knee problems and hip problems; after all, the whole posterior chain is ultimately one connected unit. Attacking the cause means correcting the poor biomechanics. Previous replies have touched on the use of orthotic inserts - these need not be £500 jobs from specialist foot clinics - relatively inexpensive inserts such as Superfeet will almost certainly do the same job but its important to make sure they address the appropriate problem. An insert for people who supinate will be worse than useless for people who over pronate, for example.
The second 'attack' is on the trauma itself. The Plantar Fascia is a ligament and as such is relatively poorly supplied with blood compared to, say muscle. This is why muscles take days to weeks to repair and ligaments take months to years. It is important to do as many things as possible to promote healing. These include: lots of ice, anti inflammatory medication such as Ibuprofen (however, please take a doctor's advice on any medication), stretching at every available opportunity (a plastic night cast to hold your foot in a stretch position works well if you can afford it and if you can put up with the faff), elevation wherever possible, rest wherever possible and massage (the rolling pin being particularly useful). The latter will hurt quite a lot.
I really feel for you as it is a really debilitating condition but be rest assured that, although it will almost certainly takes months and months to recover, recover you will, providing you attack the cause AND the symptoms. Best of luck.