No matter how much I sing I still suck?

No matter how much i practice i cant sing well. Hi my name is alexis and I have been trying to sing for quite a while about 2 to 3 years. I practice daily ranging from 30 minutes to 3 hours singing other songs word by word and I am trying to mimic singers sound by sound and I record and check my self and I do come with a lot of faults but i try to correct it to the best I can. I go up the scale on the piano with my voice and watch videos on how to use my diaphragm and all. I do all these but I still suck what does it take to get really good or aren't my genes good enough. My dad and others still say to this day that I have a nice sounding voice which I refuse to believe but horrible technique. I do not take singing lessons but if I do will it make a difference?