So my long time friend (30M) and I (30F) have gone way back, we've been friends since kindergarten. We got reconnected and become good friends after graduating college since our houses are near each other.

When I really track back the time, there were many times we supported each other and I supported his business through investing in some of my money (the business ended up closing because his friend scammed him out of his investments, I lost my money too) and us being with each other through sad, low times together and talk through it. In my head, we're good buddies. He lets me stay in his family's houses whenever we travel and we don't really count on pennies while going out together to eat (I paid my part every time we went out or we'll sometimes treat each other while going out).

I started feeling under appreciated for certain things recently. It started when I got lots of projects with great commission but I knew I can't handle it alone. I asked him to be the operational and finance part of the business, while I'll handle all sales and clients. He works on the business max 5 hours of the week because it has been set up, while I had to handle all projects and clients daily (20 hours per week but he does bear the cost of projects first and will get reimbursed later when invoices got paid). Everything went well and we split all the profits half and half - we're doing super well that he finally can save up and we can travel together.

He got a new friend and they've only been friends for a year. Just today he went out with his friend to celebrate said friend's birthday, and he got him a watch that's worth way more than the dinner the friend paid for. When it was my birthday, I got free tea (well, he said he got it from a Chinese tea master who could've sold for $1600 and then given it to me). From what I could remember, I've always tried my best to reciprocate and gave him gifts for his birthdays, but am I being unreasonable (AITA) for feeling this way?

I've tried to understand the root of these feelings by reflecting on our history, but I'm struggling to pinpoint the exact 'why'. Has anyone else experienced similar dynamics in their friendships? I'd be grateful for any insights into these kinds of situations and would love to learn more about the complexities of long-term friendships. Thank you.