I don't understand what is wrong with him and why he is changing?

My boyfriend and I have been together for 8 months now and the relationship has been amazing, the only problem we have ever had is the fact that he wants to become a professional footballer and therefore has a very busy schedule which leaves us with little time to talk to each other and see each other. Luckily we both go to the same school so we try to overcome the problem by walking home together sometimes and i go and watch most of his games to show my support, and we spend some lunch times and break times together as well as seeing each other in the afternoon a day on the weekend. HOWEVER as soon as the summer holidays started, things changed and I've felt as if we have become more distant. He got a job and his training has become more intense., hes either at the park working out or at training or at the gym or at work. His messages weren't as constant and we would see each other only once a week, then i left to go on holiday for 2 weeks.. whilst i was away we spoke once in a while. Then i returned and he didnt have a clue that i had come back until 3 days later and thats because i rung him asking if there was a problem as we hadnt spoken for 3 days which is unusual for us as we always send each other at least a good morning or goodnight message. He explained to me that he's been really busy and just hasnt had the time to talk to me and that hes just been constantly tired and dosent even talk to his own mum that much.. which i think is wrong because he needs to have a balance in his life and cant jus push away the people that he loves (please tell me if im wrong). The phone call didnt last for long as i was quite pissed off.. but he ended up sending me a message the next day apologizing and again stated that it wasnt just me because he jus does not want to socialise as hes too tired... it feels as if he thinks its a chore to talk to me.. hes my boyfriend.. he should want to talk to me not feel like he has to.. right? i replied saying that i felt unimportant and he ignored me... so 2 days later, me being the idiot that i am, messaged him again and we spoke normally for a bit until he had to sleep because he had to get up early the next morning but he still said goodnight the way he used to and sitll told me that he loved me (i doubt he meant it) .. i then asked him when i was going to see him and he told me that he was going to try and find a day and that he would message me when he was free.. its been 5 days and i have not heard from him since... its great that he's working really hard for his future and that he has aspirations, i wouldnt expect him to put me before football because its his dream and he knows he has my full support with it but i just think what hes doing is completley out of order because hes pushing me to the side like i dont exist and as if he doesnt care at all. its just strange because everything was so different at first, he made me feel so special and i dont understand how and why it changed all of a sudden and how he's jus seemed to have lost feelings for me.. sometimes i think i should jus let him have his time and understand that hes very busy at the moment but then i think again and find it strange that he cant find at least 2 minutes of his day to send me at least one message although its hard as he does not have credit therefore cant message me until hes home and from what hes told me he leaves early at around 6 and gets back super late. i honestly dont know what to do.. im currently waiting to see if he makes a day to see me so that we can talk face to face and so that i can either finish it or tell him to change but at the same time i dont want to give up on the relationship that easily... .. should i message him again? .... should i leave him through text or wait for him to give me a day? has he lost feelings for me? where did i go wrong? am i just not important to him? ive just got all these questions flying around in my head and its really bringing me down.. Has anyone got any advise on what I can do to make it better?

you need to talk to him about your future and then decide