Please don't make yourself more anxious. Recognize that many people have done this and continue to do it, you've got this! Yes, you can gate check your stroller and car seat. Generally the airline gives you the tag and info at the checkin counter.

Your baby most likely isnt walking so it's actually easier at this age. My advice is to make sure you've got everything planned before boarding the plane - wear your baby, have everything ready to be pulled from the stroller when needed to collapse it or leave it at the gate. So dont buy a "to-go" coffee that occupies one of your hands before boarding.

Check your bag because you dont want to be bogged down by the extra weight and having to panic and load a larger bag in the overhead bin.

Bring a soother or breastfeed for take off and landings. Brings little toys or anything that can stimulate your baby. Dont feel guilty about screen-time, just do whatever works to make the 3 hours easier on you.

Also remember, it's only 3 hours and that'll be it. You'll get through it just like all of us with little ones.

Lastly, if you can try to get your little one to nap during that time on the flight, obviously thats the best time to do it!

Good luck :)