If you head over to Kacha's site he has made available pdf's of the Luftwaffe victory claims for each month in 1945. They're quite detailed.
And from Alfred Price's Luftwaffe Data Book:
Serviceable Aircraft Strength 10 January 1945
Single-engined fighters   1462
Night fighters   808
Ground-attack aircraft   613
Night harassment aircraft   302
Multi-engined bombers   294
Anti-shipping aircraft   83
Long-range reconnaissance aircraft   176
Short-range and army cooperation aircraft   293
Coastal aircraft   60
Transport aircraft   269
Misc. aircraft (KG 200)   206
Total   4566 
Serviceable Aircraft Strength on 9 April 1945:
Single-engined fighters   1305
Night fighters   485
Ground-attack aircraft   712
Night harassment aircraft   215
Multi-engined bombers   37
Long-range reconnaissance aircraft   143
Short-range and army cooperation aircraft   309
Coastal aircraft   45
Transport aircraft   10
Misc. aircraft (KG 200)   70
Total   3331 
The book has detailed data on almost every unit at the time, but for obvious reasons I can't be bothered to type everything here.
This USAAF site has the USAAF losses detailed: 
http://www.usaaf.net/digest/t100.htmTotal USAAF losses in Europe January - August 1945: 4,851 aircraft. About half of what they lost in all of 1944. And that number does not include their losses in the Med.
"In the ETO (non Mediterranean MTO) during 1944, USAAF lost 1,293 fighter aircraft to enemy fighters, while losing 1,611 due to German Flak. In 1945 the ratio of fighters lost to Flak vs Luftwaffe fighters was almost 4:1."If we extrapolate that ratio to include all aircraft that's more than a thousand American aircraft shot down by the Luftwaffe in 1945.
If you don't want to believe it, don't believe it.