You are overcome with the unwholesome states, the Five Hindrances. Get a sense of what they are and arouse the wholesome states instead.
Below are the key factors of the Noble Eightfold Path that you should get a sense of through study. You should be practicing them every moment throughout the day. So you've got a lot of studying to do. The Eightfold Path is discussed in great detail here:
http://fruitofthecontemplativelife.org/forum/index.php/topic,555.0.html6. Right Effort (samma-vayama)
Mundane:
1) to prevent unwholesome states from arising (the five hindrances/the ten defilements/the seven deadly sins)
2) to abandon unwholesome states that have arisen (the five hindrances/the ten defilements/seven deadly sins)
Supramundane:
1) to arouse wholesome states that have not yet arisen: serenity, equanimity, the brahma-viharas, insight, the four foundations of mindfulness, the noble eightfold path, etc. - especially to arouse the seven factors of enlightenment leading to jhana
2) to maintain and perfect wholesome states already arisen (also implies the cultivation of the 4 jhanas)
7. Right Mindfulness and self-awareness (samma-sati) – the four foundations of mindfulness:
1) mindful awareness of the body (kaya)
2) mindful awareness of feelings/sensations (vedana) - pleasant, unpleasant, neutral (the triggers for the three unwholesome roots: greed, aversion and delusion)
3) mindful awareness of moods (citta) - the six unwholesome and wholesome roots: greed, aversion and delusion, and their opposites: generosity, loving-kindness,wisdom
4) mindful awareness/contemplation/investigation of the Five Dhammas (dhammas):
The Five Hindrances - to be abandoned
The Five Clinging Aggregates - seen as arising and passing away, that they are impermanent, suffering & non-self
The Six-sense Bases - awareness of any fetter generated by them, that they are impermanent, suffering & non-self
The Seven Factors of Enlightenment - to be developed
The Four Noble Truths - to be utterly understood
8. Right Meditation (samma-samadhi) – Four levels of jhana or meditative absorptions
1) First Jhana: The first ecstasy (jhana): bliss (piiti) and joy (sukha) born from withdrawal, accompanied by applied and sustained attention (vitakka and vicára).
2) Second Jhana: With the stilling of applied and sustained attention (vitakka and vicára), one enters and remains in the second ecstasy (jhana): joy (sukha) and bliss (piiti) born of tranquility, unification of awareness free from applied and sustained attention (vitakka and vicára) with internal assurance.
3) Third Jhana: With the fading of joy one remains in equanimity, aware and alert, physically sensitive to bliss (piiti). One enters and remains in the third ecstasy (jhana), of which the Noble Ones declare, 'equanimous and aware, one has a pleasurable abiding'.
4) Fourth Jhana: With the abandoning of grasping and aversion for pleasure and pain (sukha and dukkha) -- as with the earlier disappearance of pleasure and pain -- one enters and remains in the fourth ecstasy (jhana): purity of equanimity and awareness, with neither pleasure nor pain. This is called right meditation."
I also find walking meditation to be very blissful. There are all sorts of ways to practice it. I just keep my attention on the feet.