my 2001 Buick Regal GS will not start

I have a 2001 Buick Regal GS supercharged. It won't start. I have had this problem before... my dad replaced the starter even though the starter was not bad. It has a newer battery, even changed the key pad battery wondering if it had something to do with the automatic starter and the key pad battery being dead. Last time it wouldn't start my dad had it for a few days and it just started up again. I took it home. Had it another week or so and it wouldn't start one night. My boyfriend messed around while starting it and it started right up. DIdn't have the problem for at least a month. Again it wouldn't start. Tried again later that night, and it started up. Tried again the next morning and it hasn't started again. All the lights turn on, radio everything works.... it won't turn over. It makes a funny ticking sound but nothing happens. I am at a loss. It is almost paid off and I love my car. I do not want another payment on another car... please help!!