Welcome!
Not to be insulting, but I'm going to have to question your testing ability... It just doesn't seem possible to have 38 FC and no CYA. THe SWG shouldn't be able to keep up with the demand with no CYA, and certainly not raise FC to 38. You're new, it's not uncommon to mess up.
Second, if FC really is above 10, then your pH level is wrong. Given a TA of only 20, it's most likely somewhere in the low 6's, which is so acidic it can damage the heater core. Check out the pictures
Accurate pH test during shock levels with R-007?
Tell us some more about what's going on. How does the water look? How long are you running the pump and the SWG? Have you added anything recently? Did the CYA test sample get at all cloudy when you mixed the sample? Did you possibly make an arithmetic error and use the 25 ml sample for FC and multiply by .5? I'm assuming the TA test went blue>yellow rather than green>pink with the high FC. Did you run it to completion, where the drops made no more change in color?