I think it depends a lot on what your idea of "comfortably" is! :-) Which is probably affected by your current frame of reference: where you now live in the USA, and how ritzy/upscale your life there is.
However, like others, my first instinct is "yes", or at least certainly "more comfortable" than on the same money in USA.
For a less impressionistic view, we can look at a cost of living index (I used numbeo) which indicates that USA is 72.47 and Bulgaria is 38.39. Hence your money goes almost TWICE as far here.
Next, we can look at average wage (UNECE figures) which shows a monthly wage of $4,893 in the USA. Your income of $2,300 is less than half of this. Whereas, in Bulgaria, the average wage figure is only $627... and your income would be almost 4 times higher.
The combined effect is that you would move from a country where your income is substantially below average, with high living costs... to one where your income is FAR above average, with half the living costs. That sounds like a pretty great deal to me! :-)
From a property perspective, it should be noted that you also have a home already paid for, while many Bulgarians would need to pay rent from the above wage figure. And, most likely, as a bonus, you have a much nicer home in Sofia than you would get in your USA home town for the same money. In addition, there are still very inexpensive apartments in ski resorts (eg Bansko) and beach towns (eg Sunny Beach) here in Bulgaria, so having a holiday home (or two) is very affordable here, while out of reach for many in the USA.
Also, while the price index reflects overall expenses, some costs I would argue are disproportionately low in Bulgaria, which would benefit you even further. In particular, I think you'll find that the "carrying costs" of property (property taxes, water, electricity, home insurance, HOA/service charge) are SUBSTANTIALLY lower for your Bulgarian home than for a comparable USA property. (A few years ago I had a small house in the UK, and I was paying roughly $130 per month for EACH of water, gas, electricity, and council tax, the UK's property tax substitute. My apartment here comes in at under $100 in total.) Similarly, I think you'll be VERY pleasantly surprised by how inexpensive private health insurance (or indeed any insurance, such as for a property or a car) coverage is in Bulgaria compared with the USA.
Tax situation is always complicated for Americans because of the USA's insistence on taxing you on your worldwide income regardless of your place of residence. However, it should be noted that Bulgaria has a 10% flat rate tax, which also compares favorably with the USA.
Speaking entirely personally, I lived in Boston and San Francisco for a number of years, and while they were wonderful places to live, I would consider them to be massively expensive. However, if you're working (especially in tech, as I was) salaries are also pretty high. They become much more challenging if you're unemployed or retired.
Here, I live on a similar income to you (rental apartment + USA dividends + small pension + bit of Airbnb when Covid-19 not closing travel down). I feel that I live very well (admittedly in a pretty low key kinda way). Certainly I live WAYYYYYY better than I could live in most (all?) of USA on this income.
I teach here, and my pay is a paltry 6 euros an hour! But even this compares well with Bulgarian average hourly wage. And, because I'm so comfortable on my passive income, I don't have to work; instead, I can do it just because I enjoy it.
We've been here in Bulgaria for just over two years, and we now have a small city apartment (Plovdiv instead of Sofia), a country house in the Balkan Mountains (which we're renovating), and a ski studio in Bansko. I enjoy the change of scene / pace. I think the combined cost of all three properties would not be enough for even a small condo in Boston! (Or even, at current prices, a large new apartment in Sofia.)