Horrible experiences with gaming PC

Hello all you gamers, I built my first gaming pc back in July of 2015 and I thought it was a good gaming pc, boy I was wrong, the thing had nothing but trouble, black screens for days, monitor just turn off, and game performance was really bad. So back in September I went out and bought a R9 380 2GB (yes I know 2GB, only thing MicroCenter had in stock and he gave my 40 dollars off because they didn't have the one I wanted). This was to replace my GTX 750 1GB. Game performance didn't really increase so about October I went out and bought an I5 4460 (also I know a little on the low end but heard it doesn't bottleneck up to a GTX 980 ti). This replaced my AMD Athlon 860K. So for about 3 weeks I had a blast things were what I wanted then I started to notice things. BF4 ran about Ultra settings with 2 msaa at steady 60 fps no drops (I mean never below 60) but it started to run slower and slower each day with the FPS going down. I average about 53fps on high settings right now like wtf. CoD Black Ops 3, omg, I love that game but I have textures that don't load, only way to fix that is to put texture quality to Extra and I dont have enough VRAM so I have a PS2 game. GTA 5 wont stop crashing and when it runs it runs for about 3 times then it will never open again, and Arma 3 runs like crap, (even though it does on most rigs). I have reinstalled drivers 4 times now with everything that has a driver. Reinstalled windows 10 and 8, 3 times reinstalled all these games above and it seems to get worst every time I do. I also have rebuilt the machine 3 times now also. The big hitch here too is that my friend spent half the money of his rig and he gets better performance on Black Ops 3 and BF4 now. Just compare are computers, how does this make sense.
Mine
CPU: i5 4460
MOBO: h81M-HD3
GPU: R9 380 2GB
RAM: Team Elite Plus 8GB
HDD: 2x Western Digital Blue
PSU: EVGA SuperNova 750b
OS: Windows 10
Total price $840

His
CPU: AMD FX 6300 OC 4.2
MOBO: ASrock 970M AM3+
GPU: R7 370 4GB
RAM: Team Elite Plus 8GB
HDD: Western Digital Blue
PSU: Corsair CX 500
OS: Windows 10
Total Price $420
So after reading those specs I believe mine is quite better. I'm not jealous or in competition for the best PC and I don't go around bragging I have a beast gaming PC either, but how is it so much better? I have had the most Unsatisfying experience and the biggest money pit ever. I mean 840 bucks might not sound much but with the expenses of peripherals and a couple of other stuff I spent around 1700 bucks. I'm 15 and I have spent days upon days researching and now its distracting me from doing my homework. I need to know why this is happening or what its causing it. Any help is appreciated, thanks Toxiic.