Your brain is your biggest enemy at its default. It wants you to have an easygoing, happy-go-lucky life. It is your responsibility to rewire it to achieve your dreams. And that is very much possible.
Life is too short to hold back on something you genuinely want just to save a little money. Tomorrow, life might take that same money or double of it through fines, losses, or the unexpected. Stop depriving yourself of little joys for a few extra bucks.
Your lack of discipline towards your goals is a result of wanting things that you learned to want because other people want/have them, or because you want other people to see that you have them.
Personal goals create obsession, and obsession doesn’t wait around for discipline to grab what it wants.