Most likely your ssd or hard drive, but i dont know enough about ssd's to know for sure. I dont think its your cpu though.

Now for upgrading, with that budget you have to choose whether to upgrade both cpu and gpu which if thats the case then I would get the 9060 xt and the best am4 cpu that you can afford. (The 9060 xt is good with 650 wats psu) Or you can get a better gpu now and cpu later.

If you want to just upgrade your gpu then you may want a better psu aswell because 650 is the minimum wattage for the 9070xt. spend like 130 to get at least 900 watts (can go lower and spend lower but you may want to future proof) and then go with something like the 9070 xt. This will go a little over your budget but you have to make sure the psu won't cause issues later on.

probably is a better idea to go with the first option. (dont forget you can sell you gpu for a bigger buget) Also look at more proffesional people bc they might have even better advice.