I top off my rad fluid 01 protege LX and didn't close my cap properly and it came out. I added coolant but now there is no heat and it's over heating. Please advise.

Your stop-leak product may have also "fixed" the heater so no coolant flows there... A not-uncommon side effect of these products.

Start with engine cool, remove rad cap, start engine and turn heater on. Top up rad level and Let engine run until it get's up to normal operating temperature with cap off and add coolant as you see it go down. Watch in rad for coolant to start moving quicker, once gauge gets close to normal temperature, indicating that thermostat has opened. Wait until you see that 2 or 3 times, then top up and install rad cap. Top up coolant return bottle to proper level . You'll want to keep a close eye on coolant return bottle level for next little while. If coolant got that low in the first place, you have a leak somewhere that will have to be found.

There may be a thermostat problem, but your symtoms indicate low coolant level. When coolant is too low, it will not circulate, so you get no heat in car, and the coolant remaining in engine block overheats because no cool fluid coming in.
You need to fill the system up properly then look for leaks.
With cold engine, open radiator cap. Fill with antifreeze directly in radiator. Start engine, top up rad if level drops. Put heat control on Hot. Fan on low, heat on high. Gently rev engine and top up rad as needed. IF as engine heats up, it starts kicking fuild violently out of radiator, then the thermostat is bad. if not, then recap radiator, top up overflow bottle and you're done. Look under car for any sign of leaks. Steady dripping indicates a leak, then address that.

Did you re-fill radiator when engine cool, rad cap off and heater turned on? If not, do it with heater turned on and allow engine to get up to operating temperature and rad fan comes on once or twice, indicating coolant returning to rad for cooling . Keep an eye on coolant level and top up as required, then after fan has come on and off a couple of times, put your rad cap on properly and top up coolant return bottle to proper level. This should bleed out the air and get heater working properly again.

You might consider bleeding out the air you might have in your cooling system after you opened it,drain it to replace radiator.Let it cool down open rad cap start engine watch the burps of air come up when air locks are out coolant starts to swirl as it circulates might drop fluid level to have coolant on hand to top up after wards shut it of with rad cap off let it sit for as long as you possibly can any remaining air locks will burp out.Once coolant completely down put your rad cap back be sure fluid is full reservoir as well.Now see if you have heat.

well it might overheat because air got into system, replace the thermostant and then fill system, run van keepin an eye on the temp, it will start to run hot because coolant has not filled the motor just the radiator, when it starts running hot shut it down, wait 3 minutes and start, now this is done with cap off,after restart coolant should get sucked in get filling radiator as needed,may get messy but got to bleed cooling system. hope thius helps.

Start the engine when cool, remove rad cap and start engine and let it run with the heater on. (not defrost) Top up coolant as needed in rad, and let it run until either the rad fan comes on and off 2 or 3 times, or you can see increased flow in rad from thermostat opening. It will obviously happen after it reaches operating temperature, so watch after gauge gets close to there. Wait until you see that flow 2 or 3 times or fan comes on and off before you put cap on, and fill return bottle to proper level as well. That should cure it, by getting air out of system, and coolant flowing through heater core.

Did you re-fill coolant with heater turned on ?(not defrost) Leave rad or coolant return bottle cap off when engine cold, and turn heater on and add coolant as needed to keep level up. Let engine get to normal operating temperature, and wait for rad fan to kick in and out, indicating thermostat has opened, and coolant is circulating. Let that fan kick in 2 or 3 times and keep adding coolant as needed, and check heat periodically to see if starting to throw heat. When your getting good heat, put cap back on, top up return bottle, and you should be good. I suspect an airlock in heater core. I don't see the year anywhere so I'm guessing you have a rad cap, and if that is the case, leave it off as described, and watch for increased flow in rad when it gets up to normal operating temperature, which tells you thermostat is opening. Watch for that flow, 2 or 3 times, and you should be getting heat by then. If that isn't cure, get back to me with more info on year, engine etc. Keep me posted on your progress.

Possible that you have a headgasket leak. When the vehicle is cold open the rad cap and make sure the coolant is at the top of the rad. With the rad cap off start the engine. leave the cap off and and warm up the engine till the thermostat opens and you should at that point need to add coolant if there was any air the the cooling system. with the cap still off and the rad topped up wait until are the air bubble out of the cooling system then replace the rad cap. If this solve your problem your are OK, but if the bubbles keep coming and the vehicle keeps over heating it is possible that you have pressure from a blown heat gasket entering in the cooling system thus have the system pressure checked.