The fact that you have earned $100 is a positive thing, as you've gone from Zero to 100 in a few weeks' time only.
For a hobby, that's not too shabby. Keep at it, get your name out there, knock on doors, hand out business cards, use social media more. It'll come together, you have the skills, you have the equipment, you have the desire to get 'er done.
By the way, it might be useful for you to devote more emphasis into sign-making and banners and storefront lettering, since your HTV work is limited by the wonky functioning and small size of that older heat press.