I'm in the end of my second year (year 3 this summer) in my tennis journey and I'm a solid upper 4.0, can hang with 4.5s but not consistently. I played a lot...still playing.
I won't say that I don't doubt you...tennis is just so technical and so many strokes are needed to even be considered a 4.5 player.
Being athletic will help tremendously as I reached 3.5 within a year. But it just gets harder from there.
This was my progress:
I dont have my first few months on here because I deleted my old youtube account. But pretty much a bunch of wall hitting and ugly playing. It hurts my eyes when I watch old video of myself playing but gives me motivation to always keep improving because I've already gotten so far.