Good for you booking in to see a professional is always a good idea.
Heres my 2c
Your hair line seems pretty good, the top also seems good. As you know, No one can keep the same hairline they had at 15.
Your pics you have concern with is your hair whorl. This is exactly what i always had issues with and didn't like about my hair.
Actually yours looks ok from the pics, everyone has a hair whorl, take a hand mirror and have a good look over it by turning your back to a long mirror, have a look and see if its thining around there.
Always see a hair studio or doctor for an opinion getting on to things earlier is a very good idea as if there is a problem you may be able to prevent it.
Sometimes though tablets and self medicating etc make it worse so right now i wouldnt think you would need anything being in a relationship already can be difficult to try the meds also so just make sure if you ho down that path you are honest