Scheduling and Budgeting for Freelancers

For nearly three months, I quit my office and work on “free bread”. "Chaps" came across before that, but I did not take more than one project and did only what was within my broad, but not unlimited area of ​​competence.
I do “turnkey programming”. I specialize in projects that require related competence, I usually work with customers for a long time - for several years. I am in favor of the contractor and the customer working together and helping each other to find the optimal vision for the project. My development process looks like this:

• Incoming request: either they find me, or I respond to some order placed on one of the exchanges. I am voicing an approximate forecast of cost and terms or ask to phone / write off / clarify incomprehensible moments
• If the project is large, then the first stage is the design, which results in prototypes of pages (in balsamiq, if you need a visual design, or built up under bootstrap) + project “architecture”: used technologies, server layout, etc.
• This stage is paid separately, after which, with the help of prototypes and "architecture", I provide a detailed estimate
• Estimates are discussed, sometimes some functionality is thrown, as too expensive
• If other performers are working on the project, then I add them to your YouTrack, tasks are lined up there, assigned to the performers and traveling from todo to done

While financial information and deadlines are stored in my Google Docs. I came to the conclusion that this does not satisfy my needs, namely, I want:

• see the project schedule and current status in the calendar (does the project have time to do it)
• see how much I personally earn this month, how much I pay to contractors. Now I don’t understand whether it is profitable for me to work at all on freelancing: there are a lot of additional costs, and the cash “exhaust” is still about the same as when I worked in the office. In addition, everything is complicated by the fact that most of the projects are fixed-price, therefore, unlike office work, I risk not getting the expected amount at the end of the month if the project is late
• it is better to plan the start dates of the next projects / iterations so that the projects do not overlap each other, on the other hand, in order to avoid “holes” between orders
• have a collaboration tool for clarifying requirements, preferably integrated with a task tracker, for example, there should be a “requirement clear” button that would create a story in a task tracker. Storey can be disassembled already in the tracker

Part of this problem is solved by many existing solutions, such as Megaplan, Basecamp, SharePoint, etc. This is not about task trackers, but more about CRM-like software, which will help me better plan sales and track payments. Unfortunately, I don’t like them all, either because of the monstrous interface or because I lack some functionality.

In short, I would like a solution that simplifies a freelance / small studio customer relationship. So that you can discuss, agree, invoice, agree on an estimate, confirm the prepayment and throw the ball into production when the developers finish the demo, confirm delivery and accept the payment. At the same time, I absolutely do not want to drag task tracking into this software. All project management in CRM-systems is implemented simply monstrous. Programmers love Jira and YouTrack, not Microsoft Dynamics. This task could be solved by an individual person - “middle manager”, but I do not want to hire such a person for a number of reasons, including the fact that everything that can be automated should be automated.

At the moment, I think about writing such a software to myself, although I understand that it is quite expensive. Dear Habra community, you are faced with similar problems? I wonder how you decide them, what software do you use and whether you use it?