What could be wrong with my air conditioner, and is there anyway I could fix the problem myself?

It is probably the outside Condensor Unit..Sometimes it is a major fix and sometimes it is as simple as ants getting in to the parts. Ants like that light electrical flow for some reason and they will congregate around those circuits and short it all out.If the outside unit is not working you will not get the air you expect on the inside. You need an AC Technician to come look at it ( You might call several ones and get the best price for coming out)..You might also want them to test your thermostat while they are there.If that is old..low battery..or malfunctioned it will affect all the rest of the system.

this problem is beyond your demonstrated abilities.  The most likely cause is low refrigerant, which means you have a leak.  Yes, there are pressure gauges -- but you don't own them.  Yes, there is a leak detector device.  No, you don't own one and using it is beyond your current abilities.  You need to hire someone to check.  The relatively cheap way is to find a retired guy who still has his tools even though he can't or won't sell you replacement parts.  [Refrigerant can be bought on the Internet without a valid a/c license.]  the expensive way is to fall into the clutches of some salesman pretending to be a repairman working for a big a/c service company.  Yes, he repairs systems, too -- but he promotes new systems because he gets a fat commission for every system he sells.  [Some outfits even go so far as to fire "repair" people who don't sell a specified percentage of random customers a new system.]  If you end up having to get replacement parts ... get at least three bids and always ask them what is the minimum amount of work that can be done to make the system function again.  Hint: external units can be replaced without replacing the whole system. Another hint: the internal guts of the inside unit can also be replaced  Further hint: it is unlikely that a new, high SEER [efficiency] a/c system will pay for itself in lower electricity bills.  you get lower electricity bills by increasing insulation beyond the 4 inches the builder of your house installed, not by replacing the a/c unit.  -- grampa [from experience as homeowner in both Florida and Arizona]

it possible that the flax piscatorial .is  gone

It may need a recharge.

It may have a blockage.

It may need a new filter.

It may have a leak.

Don't guess, see a specialist and have it tested.

Whether you can fix it yourself depends on what's wrong.  If the fan on the outdoor unit isn't turning or is turning too slowly, you may be able replace the capacitor yourself assuming you know what to change and how to do it.  If the coils are freezing up there are things you could check yourself (source below) before calling for service.  If it's a refrigerant issue then hire an expert and don't DIY.  Good luck.

WRONG FORUM. The home repairs forum is over in the HOME & GARDEN  category. This is Cars & Transportation. 

there isnt enough gas being supplied, thats why after hrs when u turn it off, it comes out right and then starts lagging

Are you a qualified HVAC technician? 

No?

Sorry to be blunt, but there’s your answer. 

Your AC has been warning you for ages that it was faulty and you ignored it. That often causes additional faults  which makes diagnosing and fixing the root cause far more complicated. 

In any case, it seems likely that your aircon probably is also overdue for regular maintenance and cleaning which involves replacing or cleaning various filters and testing for Legionella which can cause a fatal respiratory disease.

You’re just going to have to call in a professional technician or live without the aircon until you can get a technician.