I will try to explain the different uses of sentir, se sentir et ressentir -
'Sentir' conveys a physical sensation usually attached to the senses of touch and smell.
Ça sent bon le pain = There's a lovely smell of bread
Je sentais son corps contre le mien = I felt his body against mine
Il sent mauvais = He smells awful
and also in a figurative sense -
On commnence à sentir les effets de la crise économique = We are beginning to feel the effects of the financial crisis
But it is always something tangible.
'Se sentir' is used to convey how you 'feel' -
Je me sens malade , fatiguée , triste... = I feel ill, tired, sad ...
Il se sentait mal à l'aise devant elle = He felt ill at ease in front of her
Vous vous sentez fatigué? = Do you feel tired?
Se sentir will be followed by an adjective or an adverb.
'Ressentir' will be followed by strong emotions in noun forms.
Ressentir de la haine ( hatred) , de la honte ( shame), de l'amour ( love) de la joie ( joy) etc...
Hope this helps!